Device communication using a reduced channel bandwidth

ABSTRACT

Systems and/or methods for supporting communications at a reduced bandwidth with a full bandwidth network such as a long-term evolution (LTE) network may be disclosed. For example, inband assignments such as downlink assignments and/or uplink grants may be provided and/or received and transmissions may be monitored and/or decoded based on the inband assignment. Additionally, information (e.g. a definition or configuration) associated with an ePDCCH may be provided and/or received and ePDCCH resources may be monitored and/or decoded based on such information. An indication for support of a reduced bandwidth by the full bandwidth network may also be provided and/or received and control channels in the reduced or narrow bandwidth may be monitored and/or decoded based on the indication. A PRACH preamble and/or a multi-type suhframe definition may also be provided and/or used for support of such a reduced bandwidth.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 61/542,114 filed Sep. 30, 2011, U.S. Provisional PatentApplication No. 61/555,876 filed Nov. 4, 2011, U.S. Provisional PatentApplication No. 61/591,632 filed Jan. 27, 2012, U.S. Provisional PatentApplication No. 61/644,835 filed May 9, 2012, and U.S. ProvisionalPatent Application No. 61/682,042 filed Aug. 10, 2012, the contents ofwhich are hereby incorporated by reference herein.

BACKGROUND

As wireless communication systems such as LTE systems mature and theirnetwork deployment evolve, network operators would like to reduce thecost of the communication network and/or maintenance of thecommunication network. One technique to reduce the cost of the networkmay be to reduce the channel bandwidth and data rate used to communicatewith devices on the network. For example, a portion of the channelbandwidth rather than the entire channel bandwidth may be supported bythe devices in the network and/or the network itself when communicationwith such devices. Unfortunately, current wireless communication systemsdo not support providing information such as channel informationincluding control channel information, uplink information, downlinkinformation, and the like on a reduced channel bandwidth.

SUMMARY

Systems and/or methods may be provided for supporting reduced channelbandwidth in wireless communications between devices such as UEs (e.g.including a low LTE UE category device) and/or low cost Machine-TypeCommunications (MTC) devices and networks that may support a fullbandwidth (e.g. a full bandwidth network). For example, in oneembodiment, a device may receive inband assignments such as downlinkassignments and/or uplink grants. Based on such inband assignments, thedevice may monitor and/or decide one or more transmissions that may beprovided by the network (e.g. in the narrow or reduced channelbandwidth).

Additionally, in an example embodiment, a device may receive information(e.g. a definition or configuration) associated with an ePDCCH that maybe used by the device. The device may then monitor and/or decode ePDCCHresources based on such information (e.g. in the narrow or reducedchannel bandwidth).

According to an embodiment, a device may also receive an indication forsupport of a narrow bandwidth by the full bandwidth network. The devicemay then monitor and/or decide channels such as broadcast or controlchannels based on the indication.

In embodiments, a PRACH preamble and/or a multi-type subframe definitionmay also be provided and/or used for support of such a reducedbandwidth. For example, a device may provide a PRACH preamble to anetwork component such as a E-UTRAN or eNB such that the networkcomponent may receive the PRACH preamble, may determine whether thedevice may be a reduced bandwidth device or another special device, mayprovide a random access response for a special device when the devicemay be a reduced bandwidth device, may receive a scheduled transmission,and/or may provide a contention resolution. Additionally, a multi-typesubframe definition may be received by a device such that the device maymonitor transmission based on the multi-type subframe definition.

The Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, not is it intended tobe used to limit the scope of the claimed subject matter. Furthermore,the claimed subject matter is not limited to any limitations that solveany or all disadvantages noted in any part of this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

A more detailed understanding of the embodiments disclosed herein may behad from the following description, given by way of example inconjunction with the accompanying drawings.

FIG. 1A depicts a diagram of an example communications system in whichone or more disclosed embodiments may be implemented.

FIG. 1B depicts a system diagram of an example wireless transmit/receiveunit (WTRU) that may be used within the communications systemillustrated in FIG. 1A.

FIG. 1C depicts a system diagram of an example radio access network andan example core network that may be used within the communicationssystem illustrated in FIG. 1A.

FIG. 1D depicts a system diagram of another example radio access networkand an example core network that may be used within the communicationssystem illustrated in FIG. 1A.

FIG. 1E depicts a system diagram of another example radio access networkand an example core network that may be used within the communicationssystem illustrated in FIG. 1A.

FIG. 2 illustrates an example of long term evolution (LTE) protocolprocessing across L1, L2 and L3.

FIG. 3 illustrates an example embodiment of a medium access control(MAC) protocol header in a communication network such as an LTE network.

FIG. 4 illustrates an example embodiment of a REG definition in adownlink control channel region with 2Tx channel state informationreference signals (CRS).

FIG. 5 illustrates an example embodiment of a REG definition in adownlink control channel region with 4Tx CRS.

FIG. 6 illustrates a table of example embodiments of a control formatindicator (CFI) codeword.

FIG. 7 illustrates a table of example embodiments of the number of OFDMsymbols that may be used for a physical downlink control channel(PDCCH).

FIG. 8 illustrates an example embodiment of a Physical Control FormatIndicator Channel (PCFICH) 4 REGs allocation according to PCI.

FIG. 9 illustrates an example embodiment of a PCFICH and PHICH REGsallocation according to PCI (e.g. using 40 RBs).

FIG. 10 illustrates a table showing an example embodiment of anorthogonal sequence according to a sequence index and spreading factor.

FIG. 11 illustrates a table showing example embodiments of PDCCH formatsthat may be supported.

FIG. 12 illustrates an example embodiment of a contention based randomaccess procedure or method.

FIG. 13 illustrates an example embodiment of a random access preambleformat.

FIG. 14 illustrates an example embodiment of a PRACH transmission intime and frequency resources.

FIG. 15 illustrates an example embodiment of smaller bandwidth supportfor a machine type communication (MTC) device.

FIG. 16 illustrates an example embodiment of a frequency resourcesselection (e.g. a procedure or method) for a PRACH transmission of a UE(e.g. a regular UE) in TDD.

FIG. 17 illustrates an example embodiment of frequency resourcesallocation (e.g. a procedure or method) for a PRACH transmission of anMTC device.

FIG. 18 illustrates an example embodiment of inband signaling that mayassign DL transmissions to a MTC device such as a low-complexity MTCdevice.

FIG. 19 depicts an example embodiment of encoding a MTC device receiveridentity as part of inband signaling.

FIG. 20 illustrates example embodiments of inband signaling that mayassign UL transmissions a MTC device such as a low-complexity MTCdevice.

FIG. 21 illustrates an example embodiment of supporting a MTC deviceusing inband signaling for assigning DL and UL data transmissions.

FIG. 22 illustrates a table listing example embodiments of availablezero-power CSI-RS configurations in FDD.

FIG. 23 illustrates an example embodiment of a zero-power CSI-RS pattern(e.g. based on 4TX or a configuration number 4).

FIG. 24 illustrates an example embodiment of a frame structure ofdownlink control channels for a MTC device (e.g. that may include or useFDD).

FIG. 25 illustrates an example embodiment of a REG definition in thezero-power CSI-RS region.

FIGS. 26 and 27 illustrate tables of example embodiments of a CFIcodeword for 2 PCFICH REGs in a MTC bandwidth and CFI codeword for 1PCFICH REG in a MTC bandwidth, respectively.

FIGS. 28 and 29 illustrate example embodiments of reduced repetitioncoding that may be provided and/or used.

FIG. 30A illustrates a table of example embodiments of different systembandwidths and RGB sizes.

FIG. 30B illustrates a table of example embodiments of different MTCbandwidths and RGB sizes.

FIG. 31 illustrates a table of example embodiments of CSI reporting.

FIG. 32 illustrates a table of example embodiments of different UEcategories and data rates.

FIG. 33 illustrates an example embodiment of a multi-type framestructure.

FIG. 34 illustrates a table of an example embodiment of a configurationof a M-PDCCH region and/or a M-PDSCH region.

FIG. 35 illustrates a table of an example embodiment of a MTCdevice-specific configuration of a M-PDCCH region and/or a M-PDSCHregion.

FIG. 36 illustrates a table of an example embodiment of TBS and amodulation order based on a MCS index (e.g. type-1).

FIG. 37 illustrates a table of an example embodiment of TBS and amodulation order based on a MCS index (e.g. type-2).

FIG. 38 illustrates an example embodiment of a PRACH transmissionstructure for a preamble that may be followed by a RACH payload.

FIG. 39 illustrates an example embodiment of a contention-based RACHprocedure that may be used with a narrower bandwidth device indication.

FIG. 40 illustrates an example embodiment of a contention-based RACHprocedure that may be used with a narrower bandwidth device indicationbased on a transmitting preamble that may have a narrower bandwidthdevice identity such as a UE and/or MTC device identity.

FIG. 41 illustrates an example embodiment of a time-shared device-RNTIsuch as a MTC-RNTI that may be used herein.

FIG. 42 illustrates an example embodiment of a PDCCH and/or PDSCHconfigured by a device RNTI such as MTC-RNTI (e.g. CRS-based).

FIG. 43 illustrates an example embodiment of a PDCCH and/or PDSCHconfigured by a device RNTI such as MTC-RNTI (e.g. DMRS-based).

FIG. 44 illustrates an example embodiment of a PDCCH and/or PDSCHconfigured by a device RNTI such as MTC-RNTI (e.g. CRS/DMRS-based).

FIG. 45 illustrates an example embodiment of a subframe-specific CCEaggregation level.

DETAILED DESCRIPTION

A detailed description of illustrative embodiments will now be describedwith reference to the various Figures. Although this descriptionprovides a detailed example of possible implementations, it should benoted that the details are intended to be exemplary and in no way limitthe scope of the application.

Systems and/or methods for supporting reduced channel bandwidth inwireless communications using devices such as UEs and/or low costMachine-Type Communications (MTC) devices may be disclosed herein. Tosupport such reduced channel bandwidth, inband assignment of downlink(DL) and/or uplink (UL) transmission resources, PCFICH and/or PDCCH overzero-power CSI-RS in a data region, PCFICH, PHICH, and/or PDCCHtransmission in a control region, multiplexing control and/or datatransmission, and/or network configuration for the UE or MTC device maybe provided and/or used as described herein. Additionally, DL receivercomplexity reduction and/or UL enhancements for such reduced channelbandwidth, PRACH procedures for such reduced channel bandwidth,broadcasting channel (e.g. SIB or SIB-x) reception or transmissionprocedures or methods for such reduced channel bandwidth, pagingprocedures or methods for such reduced channel bandwidth, data channelsfor such reduced channel bandwidth, cell selection and/or reselection insuch reduced channel bandwidth may be provided and/or used as describedherein. In example embodiments, a DCI format for the UE and/or MTCdevice that may operate on or use a reduced channel bandwidth, TBScapabilities for the reduced channel bandwidth, physical downlink sharedchannel (PDSCH) reception that may include ePDCCH in a reduced channelbandwidth, and/or device identification capabilities such as UE and/orMTC device identification that may operate on or use reduced channelbandwidth may also be provided.

FIG. 1A depicts a diagram of an example communications system 100 inwhich one or more disclosed embodiments may be implemented. Thecommunications system 100 may be a multiple access system that providescontent, such as voice, data, video, messaging, broadcast, etc., tomultiple wireless users. The communications system 100 may enablemultiple wireless users to access such content through the sharing ofsystem resources, including wireless bandwidth. For example, thecommunications systems 100 may employ one or more channel accessmethods, such as code division multiple access (CDMA), time divisionmultiple access (TDMA), frequency division multiple access (FDMA),orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), and the like.

As shown in FIG. 1A, the communications system 100 may include wirelesstransmit/receive units (WTRUs) 102 a, 102 b, 102 c, and/or 102 d (whichgenerally or collectively may be referred to as WTRU 102), a radioaccess network (RAN) 103/104/105, a core network 106/107/109, a publicswitched telephone network (PSTN) 108, the Internet 110, and othernetworks 112, though it will be appreciated that the disclosedembodiments contemplate any number of WTRUs, base stations, networks,and/or network elements. Each of the WTRUs 102 a, 102 b, 102 c, and/or102 d may be any type of device configured to operate and/or communicatein a wireless environment. By way of example, the WTRUs 102 a, 102 b,102 c, and/or 102 d may be configured to transmit and/or receivewireless signals and may include user equipment (UE), a mobile station,a fixed or mobile subscriber unit, a pager, a cellular telephone, apersonal digital assistant (PDA), a smartphone, a laptop, a netbook, apersonal computer, a wireless sensor, consumer electronics, and thelike.

The communications systems 100 may also include a base station 114 a anda base station 114 b. Each of the base stations 114 a, 114 b may be anytype of device configured to wirelessly interface with at least one ofthe WTRUs 102 a, 102 b, 102 c, and/or 102 d to facilitate access to oneor more communication networks, such as the core network 106/107/109,the Internet 110, and/or the networks 112. By way of example, the basestations 114 a and/or 114 b may be a base transceiver station (BTS), aNode-B, an eNode B, a Home Node B, a Home eNode B, a site controller, anaccess point (AP), a wireless router, and the like. While the basestations 114 a, 114 b are each depicted as a single element, it will beappreciated that the base stations 114 a, 114 b may include any numberof interconnected base stations and/or network elements.

The base station 114 a may be part of the RAN 103/104/105, which mayalso include other base stations and/or network elements (not shown),such as a base station controller (BSC), a radio network controller(RNC), relay nodes, etc. The base station 114 a and/or the base station114 b may be configured to transmit and/or receive wireless signalswithin a particular geographic region, which may be referred to as acell (not shown). The cell may further be divided into cell sectors. Forexample, the cell associated with the base station 114 a may be dividedinto three sectors. Thus, in one embodiment, the base station 114 a mayinclude three transceivers, i.e., one for each sector of the cell. Inanother embodiment, the base station 114 a may employ multiple-inputmultiple output (MIMO) technology and, therefore, may utilize multipletransceivers for each sector of the cell.

The base stations 114 a and/or 114 b may communicate with one or more ofthe WTRUs 102 a, 102 b, 102 c, and/or 102 d over an air interface115/116/117, which may be any suitable wireless communication link(e.g., radio frequency (RF), microwave, infrared (IR), ultraviolet (UV),visible light, etc.). The air interface 115/116/117 may be establishedusing any suitable radio access technology (RAT).

More specifically, as noted above, the communications system 100 may bea multiple access system and may employ one or more channel accessschemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. Forexample, the base station 114 a in the RAN 103/104/105 and the WTRUs 102a, 102 b, and/or 102 c may implement a radio technology such asUniversal Mobile Telecommunications System (UMTS) Terrestrial RadioAccess (UTRA), which may establish the air interface 115/116/117 usingwideband CDMA (WCDMA). WCDMA may include communication protocols such asHigh-Speed Packet Access (HSPA) and/or Evolved HSPA (HSPA+). HSPA mayinclude High-Speed Downlink Packet Access (HSDPA) and/or High-SpeedUplink Packet Access (HSUPA).

In another embodiment, the base station 114 a and the WTRUs 102 a, 102b, and/or 102 c may implement a radio technology such as Evolved UMTSTerrestrial Radio Access (E-UTRA), which may establish the air interface115/116/117 using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A).

In other embodiments, the base station 114 a and the WTRUs 102 a, 102 b,and/or 102 c may implement radio technologies such as IEEE 802.16 (i.e.,Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000,CDMA2000 1×, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), InterimStandard 95 (IS-95), Interim Standard 856 (IS-856), Global System forMobile communications (GSM), Enhanced Data rates for GSM Evolution(EDGE), GSM EDGE (GERAN), and the like.

The base station 114 b in FIG. 1A may be a wireless router, Home Node B,Home eNode B, or access point, for example, and may utilize any suitableRAT for facilitating wireless connectivity in a localized area, such asa place of business, a home, a vehicle, a campus, and the like. In oneembodiment, the base station 114 b and the WTRUs 102 c, 102 d mayimplement a radio technology such as IEEE 802.11 to establish a wirelesslocal area network (WLAN). In another embodiment, the base station 114 band the WTRUs 102 c, 102 d may implement a radio technology such as IEEE802.15 to establish a wireless personal area network (WPAN). In yetanother embodiment, the base station 114 b and the WTRUs 102 c, 102 dmay utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE,LTE-A, etc.) to establish a picocell or femtocell. As shown in FIG. 1A,the base station 114 b may have a direct connection to the Internet 110.Thus, the base station 114 b may not be required to access the Internet110 via the core network 106/107/109.

The RAN 103/104/105 may be in communication with the core network106/107/109, which may be any type of network configured to providevoice, data, applications, and/or voice over internet protocol (VoIP)services to one or more of the WTRUs 102 a, 102 b, 102 c, and/or 102 d.For example, the core network 106/107/109 may provide call control,billing services, mobile location-based services, pre-paid calling,Internet connectivity, video distribution, etc., and/or performhigh-level security functions, such as user authentication. Although notshown in FIG. 1A, it will be appreciated that the RAN 103/104/105 and/orthe core network 106/107/109 may be in direct or indirect communicationwith other RANs that employ the same RAT as the RAN 103/104/105 or adifferent RAT. For example, in addition to being connected to the RAN103/104/105, which may be utilizing an E-UTRA radio technology, the corenetwork 106/107/109 may also be in communication with another RAN (notshown) employing a GSM radio technology.

The core network 106/107/109 may also serve as a gateway for the WTRUs102 a, 102 b, 102 c, and/or 102 d to access the PSTN 108, the Internet110, and/or other networks 112. The PSTN 108 may includecircuit-switched telephone networks that provide plain old telephoneservice (POTS). The Internet 110 may include a global system ofinterconnected computer networks and devices that use commoncommunication protocols, such as the transmission control protocol(TCP), user datagram protocol (UDP) and the internet protocol (IP) inthe TCP/IP internet protocol suite. The networks 112 may include wiredor wireless communications networks owned and/or operated by otherservice providers. For example, the networks 112 may include anothercore network connected to one or more RANs, which may employ the sameRAT as the RAN 103/104/105 or a different RAT.

Some or all of the WTRUs 102 a, 102 b, 102 c, and/or 102 d in thecommunications system 100 may include multi-mode capabilities, i.e., theWTRUs 102 a, 102 b, 102 c, and/or 102 d may include multipletransceivers for communicating with different wireless networks overdifferent wireless links. For example, the WTRU 102 c shown in FIG. 1Amay be configured to communicate with the base station 114 a, which mayemploy a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

FIG. 1B depicts a system diagram of an example WTRU 102. As shown inFIG. 1B, the WTRU 102 may include a processor 118, a transceiver 120, atransmit/receive element 122, a speaker/microphone 124, a keypad 126, adisplay/touchpad 128, non-removable memory 130, removable memory 132, apower source 134, a global positioning system (GPS) chipset 136, andother peripherals 138. It will be appreciated that the WTRU 102 mayinclude any sub-combination of the foregoing elements while remainingconsistent with an embodiment. Also, embodiments contemplate that thebase stations 114 a and 114 b, and/or the nodes that base stations 114 aand 114 b may represent, such as but not limited to transceiver station(BTS), a Node-B, a site controller, an access point (AP), a home node-B,an evolved home node-B (eNodeB), a home evolved node-B (HeNB), a homeevolved node-B gateway, and proxy nodes, among others, may include someor all of the elements depicted in FIG. 1B and described herein.

The processor 118 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Array (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 118 may perform signal coding, dataprocessing, power control, input/output processing, and/or any otherfunctionality that enables the WTRU 102 to operate in a wirelessenvironment. The processor 118 may be coupled to the transceiver 120,which may be coupled to the transmit/receive element 122. While FIG. 1Bdepicts the processor 118 and the transceiver 120 as separatecomponents, it may be appreciated that the processor 118 and thetransceiver 120 may be integrated together in an electronic package orchip.

The transmit/receive element 122 may be configured to transmit signalsto, or receive signals from, a base station (e.g., the base station 114a) over the air interface 115/116/117. For example, in one embodiment,the transmit/receive element 122 may be an antenna configured totransmit and/or receive RF signals. In another embodiment, thetransmit/receive element 122 may be an emitter/detector configured totransmit and/or receive IR, UV, or visible light signals, for example.In yet another embodiment, the transmit/receive element 122 may beconfigured to transmit and receive both RF and light signals. It will beappreciated that the transmit/receive element 122 may be configured totransmit and/or receive any combination of wireless signals.

In addition, although the transmit/receive element 122 is depicted inFIG. 1B as a single element, the WTRU 102 may include any number oftransmit/receive elements 122. More specifically, the WTRU 102 mayemploy MIMO technology. Thus, in one embodiment, the WTRU 102 mayinclude two or more transmit/receive elements 122 (e.g., multipleantennas) for transmitting and receiving wireless signals over the airinterface 115/116/117.

The transceiver 120 may be configured to modulate the signals that areto be transmitted by the transmit/receive element 122 and to demodulatethe signals that are received by the transmit/receive element 122. Asnoted above, the WTRU 102 may have multi-mode capabilities. Thus, thetransceiver 120 may include multiple transceivers for enabling the WTRU102 to communicate via multiple RATs, such as UTRA and IEEE 802.11, forexample.

The processor 118 of the WTRU 102 may be coupled to, and may receiveuser input data from, the speaker/microphone 124, the keypad 126, and/orthe display/touchpad 128 (e.g., a liquid crystal display (LCD) displayunit or organic light-emitting diode (OLED) display unit). The processor118 may also output user data to the speaker/microphone 124, the keypad126, and/or the display/touchpad 128. In addition, the processor 118 mayaccess information from, and store data in, any type of suitable memory,such as the non-removable memory 130 and/or the removable memory 132.The non-removable memory 130 may include random-access memory (RAM),read-only memory (ROM), a hard disk, or any other type of memory storagedevice. The removable memory 132 may include a subscriber identitymodule (SIM) card, a memory stick, a secure digital (SD) memory card,and the like. In other embodiments, the processor 118 may accessinformation from, and store data in, memory that is not physicallylocated on the WTRU 102, such as on a server or a home computer (notshown).

The processor 118 may receive power from the power source 134, and maybe configured to distribute and/or control the power to the othercomponents in the WTRU 102. The power source 134 may be any suitabledevice for powering the WTRU 102. For example, the power source 134 mayinclude one or more dry cell batteries (e.g., nickel-cadmium (NiCd),nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion),etc.), solar cells, fuel cells, and the like.

The processor 118 may also be coupled to the GPS chipset 136, which maybe configured to provide location information (e.g., longitude andlatitude) regarding the current location of the WTRU 102. In additionto, or in lieu of, the information from the GPS chipset 136, the WTRU102 may receive location information over the air interface 115/116/117from a base station (e.g., base stations 114 a, 114 b) and/or determineits location based on the timing of the signals being received from twoor more nearby base stations. It will be appreciated that the WTRU 102may acquire location information by way of any suitablelocation-determination method while remaining consistent with anembodiment.

The processor 118 may further be coupled to other peripherals 138, whichmay include one or more software and/or hardware modules that provideadditional features, functionality and/or wired or wirelessconnectivity. For example, the peripherals 138 may include anaccelerometer, an e-compass, a satellite transceiver, a digital camera(for photographs or video), a universal serial bus (USB) port, avibration device, a television transceiver, a hands free headset, aBluetooth® module, a frequency modulated (FM) radio unit, a digitalmusic player, a media player, a video game player module, an Internetbrowser, and the like.

FIG. 1C depicts a system diagram of the RAN 103 and the core network 106according to an embodiment. As noted above, the RAN 103 may employ aUTRA radio technology to communicate with the WTRUs 102 a, 102 b, and/or102 c over the air interface 115. The RAN 103 may also be incommunication with the core network 106. As shown in FIG. 1C, the RAN103 may include Node-Bs 140 a, 140 b, and/or 140 c, which may eachinclude one or more transceivers for communicating with the WTRUs 102 a,102 b, and/or 102 c over the air interface 115. The Node-Bs 140 a, 140b, and/or 140 c may each be associated with a particular cell (notshown) within the RAN 103. The RAN 103 may also include RNCs 142 aand/or 142 b. It will be appreciated that the RAN 103 may include anynumber of Node-Bs and RNCs while remaining consistent with anembodiment.

As shown in FIG. 1C, the Node-Bs 140 a and/or 140 b may be incommunication with the RNC 142 a. Additionally, the Node-B 140 c may bein communication with the RNC 142 b. The Node-Bs 140 a, 140 b, and/or140 c may communicate with the respective RNCs 142 a, 142 b via an Iubinterface. The RNCs 142 a, 142 b may be in communication with oneanother via an Iur interface. Each of the RNCs 142 a, 142 b may beconfigured to control the respective Node-Bs 140 a, 140 b, and/or 140 cto which it is connected. In addition, each of the RNCs 142 a, 142 b maybe configured to carry out or support other functionality, such as outerloop power control, load control, admission control, packet scheduling,handover control, macrodiversity, security functions, data encryption,and the like.

The core network 106 shown in FIG. 1C may include a media gateway (MGW)144, a mobile switching center (MSC) 146, a serving GPRS support node(SGSN) 148, and/or a gateway GPRS support node (GGSN) 150. While each ofthe foregoing elements are depicted as part of the core network 106, itwill be appreciated that any one of these elements may be owned and/oroperated by an entity other than the core network operator.

The RNC 142 a in the RAN 103 may be connected to the MSC 146 in the corenetwork 106 via an IuCS interface. The MSC 146 may be connected to theMGW 144. The MSC 146 and the MGW 144 may provide the WTRUs 102 a, 102 b,and/or 102 c with access to circuit-switched networks, such as the PSTN108, to facilitate communications between the WTRUs 102 a, 102 b, and/or102 c and traditional land-line communications devices.

The RNC 142 a in the RAN 103 may also be connected to the SGSN 148 inthe core network 106 via an IuPS interface. The SGSN 148 may beconnected to the GGSN 150. The SGSN 148 and the GGSN 150 may provide theWTRUs 102 a, 102 b, and/or 102 c with access to packet-switchednetworks, such as the Internet 110, to facilitate communications betweenand the WTRUs 102 a, 102 b, and/or 102 c and IP-enabled devices.

As noted above, the core network 106 may also be connected to thenetworks 112, which may include other wired or wireless networks thatare owned and/or operated by other service providers.

FIG. 1D depicts a system diagram of the RAN 104 and the core network 107according to an embodiment. As noted above, the RAN 104 may employ anE-UTRA radio technology to communicate with the WTRUs 102 a, 102 b,and/or 102 c over the air interface 116. The RAN 104 may also be incommunication with the core network 107.

The RAN 104 may include eNode-Bs 160 a, 160 b, and/or 160 c, though itwill be appreciated that the RAN 104 may include any number of eNode-Bswhile remaining consistent with an embodiment. The eNode-Bs 160 a, 160b, and/or 160 c may each include one or more transceivers forcommunicating with the WTRUs 102 a, 102 b, and/or 102 c over the airinterface 116. In one embodiment, the eNode-Bs 160 a, 160 b, and/or 160c may implement MIMO technology. Thus, the eNode-B 160 a, for example,may use multiple antennas to transmit wireless signals to, and receivewireless signals from, the WTRU 102 a.

Each of the eNode-Bs 160 a, 160 b, and/or 160 c may be associated with aparticular cell (not shown) and may be configured to handle radioresource management decisions, handover decisions, scheduling of usersin the uplink and/or downlink, and the like. As shown in FIG. 1D, theeNode-Bs 160 a, 160 b, and/or 160 c may communicate with one anotherover an X2 interface.

The core network 107 shown in FIG. 1D may include a mobility managementgateway (MME) 162, a serving gateway 164, and a packet data network(PDN) gateway 166. While each of the foregoing elements are depicted aspart of the core network 107, it will be appreciated that any one ofthese elements may be owned and/or operated by an entity other than thecore network operator.

The MME 162 may be connected to each of the eNode-Bs 160 a, 160 b,and/or 160 c in the RAN 104 via an S1 interface and may serve as acontrol node. For example, the MME 162 may be responsible forauthenticating users of the WTRUs 102 a, 102 b, and/or 102 c, beareractivation/deactivation, selecting a particular serving gateway duringan initial attach of the WTRUs 102 a, 102 b, and/or 102 c, and the like.The MME 162 may also provide a control plane function for switchingbetween the RAN 104 and other RANs (not shown) that employ other radiotechnologies, such as GSM or WCDMA.

The serving gateway 164 may be connected to each of the eNode-Bs 160 a,160 b, and/or 160 c in the RAN 104 via the Si interface. The servinggateway 164 may generally route and forward user data packets to/fromthe WTRUs 102 a, 102 b, and/or 102 c. The serving gateway 164 may alsoperform other functions, such as anchoring user planes duringinter-eNode B handovers, triggering paging when downlink data isavailable for the WTRUs 102 a, 102 b, and/or 102 c, managing and storingcontexts of the WTRUs 102 a, 102 b, and/or 102 c, and the like.

The serving gateway 164 may also be connected to the PDN gateway 166,which may provide the WTRUs 102 a, 102 b, and/or 102 c with access topacket-switched networks, such as the Internet 110, to facilitatecommunications between the WTRUs 102 a, 102 b, and/or 102 c andIP-enabled devices.

The core network 107 may facilitate communications with other networks.For example, the core network 107 may provide the WTRUs 102 a, 102 b,and/or 102 c with access to circuit-switched networks, such as the PSTN108, to facilitate communications between the WTRUs 102 a, 102 b, and/or102 c and traditional land-line communications devices. For example, thecore network 107 may include, or may communicate with, an IP gateway(e.g., an IP multimedia subsystem (IMS) server) that serves as aninterface between the core network 107 and the PSTN 108. In addition,the core network 107 may provide the WTRUs 102 a, 102 b, and/or 102 cwith access to the networks 112, which may include other wired orwireless networks that are owned and/or operated by other serviceproviders.

FIG. 1E depicts a system diagram of the RAN 105 and the core network 109according to an embodiment. The RAN 105 may be an access service network(ASN) that employs IEEE 802.16 radio technology to communicate with theWTRUs 102 a, 102 b, and/or 102 c over the air interface 117. As will befurther discussed below, the communication links between the differentfunctional entities of the WTRUs 102 a, 102 b, and/or 102 c, the RAN105, and the core network 109 may be defined as reference points.

As shown in FIG. 1E, the RAN 105 may include base stations 180 a, 180 b,and/or 180 c, and an ASN gateway 182, though it will be appreciated thatthe RAN 105 may include any number of base stations and ASN gatewayswhile remaining consistent with an embodiment. The base stations 180 a,180 b, and/or 180 c may each be associated with a particular cell (notshown) in the RAN 105 and may each include one or more transceivers forcommunicating with the WTRUs 102 a, 102 b, and/or 102 c over the airinterface 117. In one embodiment, the base stations 180 a, 180 b, and/or180 c may implement MIMO technology. Thus, the base station 180 a, forexample, may use multiple antennas to transmit wireless signals to, andreceive wireless signals from, the WTRU 102 a. The base stations 180 a,180 b, and/or 180 c may also provide mobility management functions, suchas handoff triggering, tunnel establishment, radio resource management,traffic classification, quality of service (QoS) policy enforcement, andthe like. The ASN gateway 182 may serve as a traffic aggregation pointand may be responsible for paging, caching of subscriber profiles,routing to the core network 109, and the like.

The air interface 117 between the WTRUs 102 a, 102 b, and/or 102 c andthe RAN 105 may be defined as an R1 reference point that implements theIEEE 802.16 specification. In addition, each of the WTRUs 102 a, 102 b,and/or 102 c may establish a logical interface (not shown) with the corenetwork 109. The logical interface between the WTRUs 102 a, 102 b,and/or 102 c and the core network 109 may be defined as an R2 referencepoint, which may be used for authentication, authorization, IP hostconfiguration management, and/or mobility management.

The communication link between each of the base stations 180 a, 180 b,and/or 180 c may be defined as an R8 reference point that includesprotocols for facilitating WTRU handovers and the transfer of databetween base stations. The communication link between the base stations180 a, 180 b, and/or 180 c and the ASN gateway 182 may be defined as anR6 reference point. The R6 reference point may include protocols forfacilitating mobility management based on mobility events associatedwith each of the WTRUs 102 a, 102 b, and/or 102 c.

As shown in FIG. 1E, the RAN 105 may be connected to the core network109. The communication link between the RAN 105 and the core network 109may defined as an R3 reference point that includes protocols forfacilitating data transfer and mobility management capabilities, forexample. The core network 109 may include a mobile IP home agent(MIP-HA) 184, an authentication, authorization, accounting (AAA) server186, and a gateway 188. While each of the foregoing elements aredepicted as part of the core network 109, it will be appreciated thatany one of these elements may be owned and/or operated by an entityother than the core network operator.

The MIP-HA may be responsible for IP address management, and may enablethe WTRUs 102 a, 102 b, and/or 102 c to roam between different ASNsand/or different core networks. The MIP-HA 184 may provide the WTRUs 102a, 102 b, and/or 102 c with access to packet-switched networks, such asthe Internet 110, to facilitate communications between the WTRUs 102 a,102 b, and/or 102 c and IP-enabled devices. The AAA server 186 may beresponsible for user authentication and for supporting user services.The gateway 188 may facilitate interworking with other networks. Forexample, the gateway 188 may provide the WTRUs 102 a, 102 b, and/or 102c with access to circuit-switched networks, such as the PSTN 108, tofacilitate communications between the WTRUs 102 a, 102 b, and/or 102 cand traditional land-line communications devices. In addition, thegateway 188 may provide the WTRUs 102 a, 102 b, and/or 102 c with accessto the networks 112, which may include other wired or wireless networksthat are owned and/or operated by other service providers.

Although not shown in FIG. 1E, it should, may, and/or will beappreciated that the RAN 105 may be connected to other ASNs and the corenetwork 109 may be connected to other core networks. The communicationlink between the RAN 105 the other ASNs may be defined as an R4reference point, which may include protocols for coordinating themobility of the WTRUs 102 a, 102 b, and/or 102 c between the RAN 105 andthe other ASNs. The communication link between the core network 109 andthe other core networks may be defined as an R5 reference, which mayinclude protocols for facilitating interworking between home corenetworks and visited core networks.

As described above, as wireless communication systems such as LTEsystems mature and their network deployment evolve, network operatorsmay want or wish to reduce the cost of the devices that may communicatewith LTE network. One technique to reduce the cost of the device may beto reduce the channel bandwidth and data rate used to communicate withthe network. For example, a portion of the channel bandwidth rather thanthe entire channel bandwidth may be supported by the devices in thenetwork and/or the network itself when communication with such devices.Unfortunately, current wireless communication systems do not supportproviding information such as channel information including controlchannel information, uplink information, downlink information, and thelike on a reduced channel bandwidth.

For example, an example for the application of wireless communicationstechnology may include Machine-Type Communications (MTC). MTC may be amarket that may be likely to expand in the foreseeable future aswireless technology advances. Devices such as MTC devices or other UEdevices may be targeted for low-end (e.g. low cost, low data rate)applications that may be handled by the GSM/GPRS network. Unfortunately(e.g. due to the low cost of operations or reduced operation supportedwith such a device), the motivation for migrating such a device to anetwork such as an LTE network may be dampened. In an embodiment, thereluctance of migrating to such a device to a network such as an LTEnetwork may cost network operators in terms of maintaining multiple RATsand/or may prevent operators from reaping the maximum benefit out oftheir spectrum (e.g. given a non-optimal spectrum efficiency ofGSM/GPRS). Additionally, given the likely high number of such devices,the overall spectrum resource a network operator may use for serviceprovision in GSM/GPRS may be increased (e.g. significant or high) and/ormay be inefficiently assigned. As such (e.g. as described herein),systems and/or methods (e.g. low cost systems and/or methods) formigrating such a device to a network such as an LTE network may beprovided and/or used. Such systems and/or methods may ensure that theremay be a clear business benefit to MTC device vendors and operators formigrating low-end MTC devices from GSM/GPRS to LTE networks.

As described herein, a low cost device such as a UE or MTC device maygenerally include, but may not be limited to, certain reduction of ageneral WTRU capability and functionality such as lower data rate, lowerpower consumption and simpler implementation, and the like that mayreduce the implementation complexity include lowering the radiofrequency (RF) component count for such devices. For example, in suchdevices a reduced number of radio access technologies (RATs) or RFchains may be supported. Additionally, in such devices, reducing themaximum applicable transmission power in the uplink (UL) for such adevice, the maximum supported receive (Rx) or transmit (Tx) channelbandwidth may be reduced and/or a half-duplex FDD mode may be supported.

Additionally, the introduction of low-cost devices such as MTC devicesinto networks may be provided while maintaining service coverage and theuse of such devices should not result in a penalty in terms ofachievable spectrum efficiency during operation. In example embodiments,low-cost devices such as MTC devices when introduced into a network maybe inter-operable with legacy UEs or WTRUs (e.g. Release 8-10 LTE WTRUs)(e.g. such devices should be able to communicate on an existing LTEradio on a carrier). In addition, the low-cost devices such as MTCdevices may still support mobility and roaming.

In example embodiments, as described herein, the low-cost devices suchas MTC or UE devices that may use a reduced channel bandwidth may beused in a LTE radio network and/or protocol architecture. The LTE radionetwork may provide radio bearers to which IP packets may be mappedprotocol when processing in both the DL and/or UL directions. In such anetwork, the PDCP may perform IP header compression, ciphering in theControl Plane, integrity protection for transmitted data and may providein-sequence delivery and duplicate removal during mobility. The RLC mayalso perform segmentation and/or concatenation, re-transmissionhandling, and duplicate detection and in-sequence delivery. The MAC thatmay be used in the network may multiplex logical channels, performsHybrid ARQ, and does DL and UL scheduling. The Physical Layer processingmay include functionalities like channel coding and/or decoding,modulation and/or demodulation, multiple antenna mapping, and the like.The LTE radio protocol architecture for the user plane PDCP, RLC, MACand L1 that may be used may be shown in FIG. 2.

According to example embodiments, LTE data transmission in the DL and ULmay be or may include DL-SCH and UL-SCH transport channels. Eachtransport channel may be mapped to a corresponding physical channel. Inthe DL or DL direction, the DL-SCH transmitted to a handset may bemapped to the HS-PDSCH and may include one or more transport blocks(e.g. two in the case of Spatial Multiplexing) per TTI (e.g. subframe).Similarly, in the UL or UL direction, the PUSCH may include a transportblock per TTI (e.g. in R8) or up to two transport blocks per TTI (e.g.in R10) when Spatial Multiplexing may be used.

In addition to the physical channels that may carry data or controlsignaling such as RRC, there may also be physical channels without acorresponding transport channel including L1/L2 control channels. SuchL1/L2 control channels may be mainly used to send DL Control Information(DCI) to handsets. In embodiments, DL control information may includeinformation that may be used by a terminal to properly decode the PDSCHin a TTI, may assign PUSCH transmission resources to handsets, mayinclude power-control commands, and the like.

Additionally, in such a network, DCIs may be sent to handsets using thePDCCH. For example, in a given subframe (TTI), a handset may monitor thePDCCH for DCI messages. When a DCI indicating a DL assignment may bereceived, the handset may attempt to demodulate and decode a PDSCH inthe data region of that same subframe. Similarly, when the handsetdecodes an UL grant on the PDCCH in subframe n, it may prepare for ULtransmission of a PUSCH in subframe n+4.

According to an example embodiment, reception of DCI's in the PDCCHinside the Control Region of a subframe may be part (e.g. an integralpart) of the DL and UL channel assignment procedures or methods forPDSCH and PUSCH (e.g. in LTE). DCIs, for example, that may be inside thePDCCH of a Control Region may announce which handset(s) may have a DLtransmission allocated in the Data Region of that subframe and whichtransmission resources may be allocated. Furthermore, the DCIs that maybe carrying the DL assignments or UL grants may include specifics withrespect to the encoding format chosen for the PDSCH or PUSCH such asMCS, TB size (e.g. transport block size or TBS), RV, and the like.

When a device such as a UE or handset decodes the PDSCH carrying 1 or 2TBs, the device may also decode MAC and RLC header information that maybe part of the PDSCH transmission. In an embodiment, informationincluded within these MAC or RLC headers (e.g. in R8 to R10 LTE) maypertain to the functionalities implemented by the MAC and RLC protocol.For example, the MAC and RLC header fields (e.g. in LTE) may includecounter and PDU sequence number fields to support re-assembly andin-sequence detection and/or they may include MAC sub-headers toindicate presence of logical data versus control channels or themultiplexing of MAC control elements (e.g. as shown in FIG. 3).Additionally, the DL assignment for a PDSCH in the same subframe, or theUL grant in DL subframe n that may pertain to a PUSCH transmissionresource in UL subframe n+4 may be sent to the handset through the PDCCHDCIs in the form of separate physical layer signaling using the PDCCH(e.g. in LTE).

In an example embodiment, downlink control channels (e.g. in LTE) mayachieve uniform coverage in a cell while providing robustness in highmobility irrespective of the UE architecture or geometry. The LTEdownlink control channels may occupy the first one to three OFDMsymbol(s) in each subframe according to or based on the overhead of thecontrol channels. Such a dynamic resource allocation to handle downlinkcontrol channel overhead may enable or allow efficient downlink resourceutilization that may result in or provide a higher system throughput.Different types of downlink control channels may be (e.g. in general)transmitted within the downlink control channel region in each subframeincluding, for example, a PCFICH (Physical Control Format IndicatorChannel), a PHICH (Physical Hybrid-ARQ Indicator Channel), a PDCCH(Physical Downlink Control Channel), and the like. In an exampleembodiment, the downlink control channel resource unit may be defined asor may include four contiguous REs in frequency domain called REG(Resource Elements Group) as shown in FIGS. 4 and 5. For example, if aCRS may be located in the same OFDM symbol, the REG may be fourcontiguous REs without a CRS. FIGS. 4 and 5 show the definition of REGsaccording to the number of CRS ports.

According to an example embodiment, a PCFICH (Physical Control FormatIndicator Channel) may be provided and/or used. The PCFICH may betransmitted in the 0th OFDM symbol in each subframe and it may indicatethe number of OFDM symbols that may be used for downlink control channelin the subframe. In an embodiment, the subframe-level dynamic downlinkcontrol channel resource allocation may be provided or implemented byusing the PCFICH. For example, a UE may detect a CFI (Control FormatIndicator) from a PCFICH and the downlink control channel region may beindicated in the subframe according the CFI value. FIG. 6 shows a CFIcodeword that may be detected from the PCFICH, and FIG. 7 shows a tableof an available number of OFDM symbols that may be used for the downlinkcontrol channel according to the duplex mode, subframe type, and/orsystem bandwidth. In one embodiment (e.g. as an exception), the PCFICHmay be skipped if a subframe may be defined as non-PDSCH supportablesubframe so a UE may not try to detect PCFICH in the subframe.

As described herein, in an example embodiment, four REGs may be used forPCFICH transmission in the 0th OFDM symbol in a subframe and the REGsmay be uniformly distributed in a whole system bandwidth to exploitfrequency diversity gain. Additionally, the starting point of PCFICHtransmission may be different based on a physical cell-ID (PCI) as shownin FIG. 8.

Additionally, in an embodiment, a frequency shift of the PCFICH that maybe tied with a cell-ID may enable or allow the performance of a PCFICHdetection by, for example, avoiding PCFICH collision among multipleneighbor cells while achieving a diversity order four from itsdistributed allocation. At a UE receiver, downlink control channeldetection may be performed. Such a downlink control channel may firstdecode the PCFICH to determine or figure out the number of OFDM symbolin the subframe. Given that downlink control resource may be defined byPCFICH, the PCFICH detection error may result in or provide a loss of adownlink grant, an uplink grant, and/or PHICH reception.

In embodiments, a PHICH (Physical Hybrid-ARQ Indicator Channel) may alsobe provided and/or used. For example, the PHICH may be used to transmitACK or NACK corresponding to the PUSCH transmitted in an uplinksubframe. A PHICH may further be transmitted in distributed manneracross system bandwidth and OFDM symbols within downlink controlchannel. The number of OFDM symbols may be defined as a PHICH durationand may be configurable via higher layer signaling. According to anembodiment, the PHICH resource position may vary according to PHICHduration, which may be different from the PCFICH. FIG. 9 shows thePCFICH and PHICH resource allocations. As shown in FIG. 9, multiplePHICH groups may be defined in a cell. Additionally, a PHICH group mayinclude multiple PHICHs with orthogonal sequences and the PHICH for a UEmay be defined dynamically with resource information in uplink grantsuch as a lowest PRB index (I_(PRB) _(_) _(RA) ^(lowest) ^(_) ^(index))and DM-RS cyclic shift (n_(DMRS)). As such, in an embodiment, two indexpairs (PHICH group index: n_(PHICH) ^(group), PHICH sequence index:n_(PHICH) ^(seq)) may indicate the PHICH resource for a specific UE. Inthe PHICH index pair (n_(PHICH) ^(group),n_(PHICH) ^(seq)) each indexmay be defined as follows

n _(PHICH) ^(group)(I _(PRB) _(_) _(RA) ^(lowest) ^(_) ^(index) +n_(DMRS))mod N _(PHICH) ^(group),

n _(PHICH) ^(seq)=(└I _(PRB) _(_) _(RA) ^(lowest) ^(_) ^(index) /N_(PHICH) ^(group) ┘+n _(DMRS))mod 2N _(SF) ^(PHICH),

where the N_(PHICH) ^(group) may denote the number of PHICH groupavailable in the system with following definition

$N_{PHICH}^{group} = \left\{ \begin{matrix}\left\lceil {N_{g}\left( {N_{RB}^{DL}/8} \right)} \right\rceil \\{2 \cdot \left\lceil {N_{g}\left( {N_{RB}^{DL}/8} \right)} \right\rceil}\end{matrix} \right.$

where Ng may be 2-bit information that may be transmitted via a PBCH(Physical Broadcasting Channel) and the information may be withinN_(g)∈{⅙, ½, 1, 2}. According to an example embodiment, the orthogonalsequence that may be used herein may be based on the spreading factorand/or sequence index as shown in the table of FIG. 10.

In an example embodiment, a PDCCH (Physical Downlink Control Channel)may be provided and/or used. The PDCCH may be defined with one ormultiple consecutive CCE (Control Channel Element) resources in whichone CCE may include multiple REGs (e.g. nine REGs). The number ofavailable CCE (N_(CCE)) may be defined with N_(CCE)=└N_(REG)/9┘ whereN_(REG) may be the number of REGs that may not be assigned to PCFICH orPHICH. The table in FIG. 11 shows example embodiments of available PDCCHformats that may be used herein by definition of number of consecutiveCCEs.

Additionally, a Random Access (RA) method or procedure and/or a PRACH(Physical Random Access Control Channel) may be provided and/or used. Inembodiments (e.g. in LTE), the Random Access method or procedure may beused in one or more events including one or more of the following: for aRRC Connection Request such as for an initial access or to register; forRRC Connection re-establishment such as following a radio link failure(RLF); during a handover to access a target cell; to obtain ULsynchronization such as when UL synchronization may be lost and DL datamay arrive or there may be UL data to send; when the UE may have UL datato send and there may be no dedicated resources (e.g. no PUCCH resourceshave been assigned to the UE); for positioning purposes such as whentiming advance may be used for UE positioning; and the like.

According to an example embodiment, there may be two forms of a RAprocedure that may be performed. One form may include a contention-basedRA procedure, which may apply to a portion of the forgoing events (e.g.the first five events above). Another form may include anon-contention-based, which may apply to a handover, DL data arrival,and/or positioning. When a contention-based random access procedure maybe applied, at least two devices or mobiles may select the sameresources (e.g. preamble and opportunity) for random access, and, thus,the contention situation may be resolved. The non-contention basedprocedure may be applicable when the base station may signal a reservedrandom access preamble to a device or mobile, for example, at ahandover, uplink synch failure, and/or for positioning. In thisembodiment, information (e.g. essentially timing) may be acquired at therandom access response

A contention-based Random Access procedure that may be provided and/orused may be shown in FIG. 12. The contention-based procedure asillustrated in FIG. 12 may be characterized by the following. At 1, aRandom Access Preamble on RACH (e.g. a PRACH preamble) may betransmitted by a UE and received by a base station or eNB. The RandomAccess Preamble or RACH (e.g. the PRACH) may be 6 bit to carry includinga 5 bit preamble ID and 1 bit to indicate the information on the size ofa message (e.g. message 3).

As shown in FIG. 12, at 2, a Random Access response that may begenerated by MAC on DL-SCH may be sent from the base station or eNB tothe UE. According to an example embodiment, the Random Access responsemay be addressed to a RA-RNTI on a L1/L2 control channel. Additionally,the Random Access response may include a Preamble ID, Timing Alignment,Initial Uplink Grant and Temporary C-RNTI, and the like.

At 3, a scheduled transmission may be provided from the UE to the basestation or eNB on, for example, a UL-SCH. The size of the transportblocks that may be used herein (e.g. at 3) may depend on the UL grantthat may be conveyed at 2. Additionally, at 3, for initial access, theRRC Connection Request generated by the RRC layer may be conveyed. Aftera radio link failure (RLF), the RRC Connection Re-establishment Requestgenerated by the RRC layer may be conveyed and/or after a handover, inthe target cell, the ciphered and integrity protected RRC HandoverConfirm generated by the RRC layer may be conveyed. In an embodiment(e.g. in response to other events), at least the C-RNTI of the UE may beconveyed.

As shown in FIG. 12, at 4, a contention resolution may be provided fromthe base station or eNB to the UE, for example, on a DL-SCH. Forexample, at 4, an early contention resolution may be used and/or providewhere the eNB may not wait for a NAS reply before resolving acontention.

In an example embodiment, a preamble transmission procedure and/ormethod via layer 1 may be provided and/or used. For example, before thepreamble transmission procedure, a layer 1 may receive the followinginformation from higher layers: random access channel parameters (e.g. aPRACH configuration, frequency position, and/or preamble format);parameters for determining the root sequences and their cyclic shifts inthe preamble sequence set for the cell (e.g. index to root sequencetable, cyclic shift (N_(CS)), and/or set type (e.g. unrestricted orrestricted set)), and the like.

After receiving such information, the preamble transmission proceduremay be performed. For example, a layer 1 receives preamble transmissionrequest from higher layers. A preamble index, preamble transmissionpower (e.g. PREAMBLE_TRANSMISSION_POWER), associated RA-RNTI, and PRACHresources may be indicated by higher layers as part of the request.Then, a preamble may be selected from the preamble sequence set usingthe preamble index and/or the preamble may be transmitted withtransmission power PREAMBLE_TRANSMISSION_POWER on the indicated PRACHresource. In an embodiment, if no associated PDCCH with RA-RNTI may bedetected, the physical random access may be is exited. If an associatedPDCCH with RA-RNTI may be detected, the corresponding DL-SCH transportblock may passed, provided, or transmitted to the higher layers and thephysical random access procedure may be exited.

According to an example embodiment (e.g. in existing LTE systems), twogroups of RACH preambles may be broadcast in the System InformationBlock 2 (SIB2) (e.g. using the preamble transmission procedure). Thebroadcast preambles may be used by each of the UEs in the cell.

A PRACH time and frequency structure may be provided and/or used. In anexample embodiment, the structure may include the physical layer randomaccess preamble shown in FIG. 12. For example, as shown in FIG. 13, thephysical layer random access preamble that may be used may include acyclic prefix of length T_(CP) and a sequence part of length T_(SEQ).The allocated TTIs for the RACH may be decided by the eNB according tothe cell coverage requirement.

Additionally, in the frequency domain, a random access burst may occupya bandwidth corresponding to 6 resource blocks (e.g. 6 RBs may equal1.08 MHz) for both frame structures. PRACH transmission intime-frequency resources may be illustrated in FIG. 14.

The transmission of a random access preamble, if triggered by the MAClayer, may be restricted to certain time and frequency resources. Suchresources may be enumerated in increasing order of the subframe numberwithin the radio frame and the resource blocks in the frequency domainsuch that index 0 may correspond to the lowest numbered resource blockand subframe within the radio frame.

In example embodiments, system information for a cell that may includeoperating parameters (e.g., UL and DL bandwidth), resources for randomaccess, neighbor lists for measurements, and the like may be broadcastby the cell in information blocks. For example (e.g. in LTE), there maybe a master information block (MIB) and a number of system informationblocks (SIBs). The MIB may be transmitted on a known schedule (e.g.subframe 0 of each frame) and a known set of resources, (2nd timeslot ofthe subframe, center 6 RBs). The MIB may provide a small amount ofinformation including the system frame number (SFN) and the DL BW of thecell to enable UEs to read a SIB 1. The SIB 1 may have a known schedule(e.g. subframe 5 each 80 ms), but not a known set of resources that maybe PDSCH resources. In a subframe in which the SIB 1 may be present oravailable, a PDCCH in that subframe using a SI-RNTI may provide thelocation of the SIB 1 resources. A UE may read the PDCCH to obtain theSIB 1 location to read the SIB 1. According to an example embodiment,the SIB 1 may provide critical information for cell selection includingthe cell ID and the PLMN ID, certain operating parameters such as theTDD UL/DL configuration (e.g. for TDD only), and/or schedulinginformation for the other SIBs. A UE in Idle Mode may read the SIBs toperform cell selection and reselection as well as to obtain theparameters that may be used for random access. A UE in a connected modemay read the SIBs, for example, to determine if changes may haveoccurred or the eNB may provide system information to a connected UE viadedicated signaling.

In example embodiments, a UE may periodically monitor the PDCCH for DLassignments on the PDCCH masked with a P-RNTI (Paging RNTI) both in anIdle Mode and in a Connected Mode. When such a DL assignment using theP-RNTI may be detected, the UE may demodulate the assigned PDSCH RBs andmay decode the Paging Channel (PCH) carried on that PDSCH.

In the Idle Mode, the specific Paging Frame (PF) and subframe withinthat PF, for example, the Paging Occasion (PO) that the UE may monitorwithin the Paging Channel may be determined based on the UE ID andparameters (e.g. two parameters) specified by the network such as PagingCycle length (e.g. in frames) and the Number of paging subframes perpaging cycle. The UE ID, in an embodiment, may be the UE IMSI mod 4096.Such Paging Occasions may include pages specifically for the UE, or theymay include system information change pages directed to each of the UEs.

From the network perspective, there may be multiple PFs per paging cycleand multiple PO's within a PF, for example, more than one sub-frame perpaging cycle may carry PDCCH masked with a P-RNTI. Additionally, fromthe UE perspective, a UE may monitor a PO per paging cycle, and such aPO may determined by the parameters specified herein (e.g. above),provided to the UE via system information, dedicated signalinginformation, and the like.

In Connected Mode, the UE may receive pages related to systeminformation change, for example, it may not receive UE-specific pagessuch as those that may be used for an incoming call. As such, a UE inthe Connected Mode may not monitor a specific PO. Rather, it simply maytry to receive pages at the same rate as a UE in the Idle Mode using thecell-specific paging cycle. Additionally, for FDD, the PO may be limitedto subframes 0, 4, 5 and 9 and/or for TDD, the PO may be limited tosubframes 0, 1, 5 and 6.

As described herein, a reduced bandwidth for a physical downlink controlchannel (PDCCH) and/or a physical downlink shared channel (PDSCH) may beprovided and/or used for a network and/or a device such as a MTC deviceor UE that may support such a reduced bandwidth. Currently, an issuewhen operating a device such as an LTE device or UE and/or a MTC devicethat may support a smaller or reduced bandwidth on a regular channelsuch as a regular LTE channel may be an inability of the device toreceive a DL control channel or signals from the network and/or a cell.Such an issue may occur, because the control channels such as the LTEcontrol channels and control signals may be spread and/or distributed intransmission such that the channels and signals may use the entire orfull bandwidth of the cell and by definition the smaller or reducedbandwidth device may be able to receive a portion such as the centerportion of the cell bandwidth. For example, as shown in FIG. 15, adevice such an MTC device may read a portion of the system bandwidth. Assuch, in an embodiment, if a cell such as an LTE cell may be configuredas 10 MHz bandwidth and a device such as a low-complexity MTC device orUE may support 5 MHz or smaller bandwidth, the 10 MHz network, cell,and/or carrier may use 50 resource blocks (RBs), but the device that mayacquire a center frequency fc of the carrier may read a portion of those50 RBs such as the center 25 RBs of that cell instead of the entire 50RBs. The terminologies RBs, physical resource blocks (PRBs), andPRB-pair may be used interchangeably.

By not reading the entire bandwidth and having such information (e.g.control channel information) being distributed or spread through theentire bandwidth, the device such as the low-complexity MTC device or UEmay miss reading part of the information such as the control channels,and the like. For example, the device may miss a part of PCFICH channel(e.g. since each of its 4 REGs may spread apart by approximately ¼ ofthe total cell bandwidth), and, thus, may not be able to accuratelydecode the CFI which indicates the number of OFDM symbols for thecontrol region in that subframe and may not be able to calculate thetotal number of CCEs affecting the determination of the individual PDCCHlocations.

Additionally, due to the same Rx bandwidth limitation, the device maysuch as the low-complexity MTC or UE may not be able to decode the PDCCHand common search space signals and, as such, may not be able to receivethe common control signals such as SI-RNTI and P-RNTI that may be partof the detection of the occurrences of system information broadcast andpaging messages. According to an example embodiment, the RNTI, or RadioNetwork Temporary Identifier, may identify a UE (User Equipment) when anRRC (Radio Resource Control) connection may exist and may include C-RNTI(Cell RNTI), S-RNTI (Serving RNC RNTI), U-RNTI (UTRAN RNTI), and thelike.

Similarly, in an embodiment, the UE may not be able to receive theinformation of DL assignments or UL grants that may be carried as partof the DCIs in the PDCCH that may be transmitted across the entiresystem bandwidth in the first one to three time-domain OFDM symbols ofthe frame making up the Control Region of a network or system (e.g. theLTE network or system).

Currently, support for reduced bandwidth on a device such as alow-complexity MTC device or UE may be difficult, because such devicesmay be unable to demodulate the entire transmission bandwidth (BW) thata PDCCH such as a legacy LTE PDCCH may use. For example, decoding a R8PDCCH may result in a much higher decoding complexity (“operations persecond”) than the PDSCH itself when the PDSCH may carry approximately anorder of 10's or 100 kbps. For high-performance devices such as LTEdevices or UEs, the decoding complexity for an order of Mbps PDSCHs mayalso be higher than for the PDCCH, which may be acceptable for suchdevices. However, for low-complexity MTC devices using the reduced datarates, the legacy R8 PDCCH based assignment protocol may be thedetermining factor in terms of decoding complexity. As such, the PDCCHdesign aspects of embodiments described herein for low-complexitydevices may provide decoding at a reduced receive bandwidth, and also,may reducing the PDCCH decoding complexity.

Additionally, legacy devices such as R8 LTE handsets may follow theapproach that they wake up each TTI (e.g. subframe), may decode thePDCCH, and may then go back idle if there may be no received DLassignment for PDSCH in that subframe. In such an embodiment, theactivity of legacy R8 handsets may be regulated by a DRX protocolsitting on top of this approach, which may kick-in to reduce decodingactivity as a function of timers and the number of received DL messages.To reduce Tx/Rx activity of devices that may support a reduced bandwidthsuch as a MTC device or UE, to wake up and decode both control and data,embodiments described herein may reduce (e.g. by a factor 10 or higher)the number of subframes that a device may decode. As such, system and/ormethods described herein may enable the reduction of implementation costthrough support for reduced channel bandwidths when operating devicessuch as low-cost MTC devices or UEs that may not provide an impact ontothe network and its performance during operation.

A reduced bandwidth for PDSCH may also be provided and/or used inembodiments. For example, as described herein, a bandwidth reduction forcontrol channels in a network or system (e.g. a LTE system) that mayhave a wider bandwidth may result in downlink control channel receptionproblems when, for example, time time-division multiplexing (TDM) baseddownlink control channel transmission may be used. As described herein,the reduced bandwidth may lose at least a portion of control channelinformation resulting in downlink control channel reception degradation.To address such a problem or issue, the reduced bandwidth may be appliedfor data regions (e.g. PDSCH regions) and full bandwidth reception maybe used for control channel regions (e.g. PDCCH). Although such anembodiment may not provide cost reduction in the RF, there may be a costreduction in the baseband chipset as its soft buffer size becomessmaller and channel estimation complexity for PDSCH demodulation may bereduced.

Additionally, other challenges including PDSCH resource mapping may beincurred as the system supports full bandwidth. For example, thepopulation of a device such as low-cost MTC (LC-MTC) may be much largerthan that of regular devices such as LTE device that may be operating onthe network. In such an embodiment, PDSCH resource utilization may be aproblem or an issue. Also, other broadcasting and multi-casting channelstransmitted in the PDSCH region may be changed as described herein toensure that the devices that support such a reduced bandwidth such asthe LC-MTC devices receive broadcasting and multi-casting channels.

Current physical random access channel (PRACH) may also be affected orincur problems or issues due to bandwidth reduction. For example,although a PRACH such as a Rel-8/9/10 PRACH may support different systemBWs such as 1.4, 3, 20 MHz, and the like, a UE with different BWcapability from a system BW may not currently be supported (e.g. inLTE). In other words, current systems or implementations (e.g. LTE) mayrequire that the supported BW of a UE or device may have to be equal to20 MHz, which may be the maximum system BW.

Additionally, with the increased development of current cellularnetworks such as LTE networks and their advancement (e.g. LTE-A),communications such as MTC communications via such cellular networkswith widespread coverage may constitute or account for quite a bit ofthe internet services that may be used. Unlike traditional voice and webstreaming, services or communications such as MTC services orcommunications may often have different requirements on a communicationsystem due to their specific features such as sensing, control ormonitoring application, and the like. For example, a large number ofservices such as MTC services may be non-real time and may typicallyconsume less bandwidth than traditional web browsing or videoapplication and, thus, may be supported by less BW than current regulardevices or UEs. However, current standards (e.g. LTE standards) may notaddress the issue of BW reduction for devices such as MTC devices or UEs(e.g. that may support a reduced bandwidth). As such, procedures,methods, and/or techniques to achieve BW reduction when conducting RACHtransmission for devices that may support such a reduced BW includingMTC devices and/or use may be desired and/or important.

Currently (e.g. the current LTE standard), in embodiments, a PRACHfrequency resource (e.g. consecutive 6RBs) within the supported systemBW may be allocated in an uplink subframe in FDD (e.g. a framestructure 1) and up to 6 PRACH frequency resources in an uplink subframemay be configured in TDD (i.e., frame structure 2). These PRACHfrequency resources may be configured via a system information blocktype 2 (SIB2) that may be transmitted with an associated PDCCH (e.g.with SI-RNTI). Regular devices or UEs may randomly select one of thesetime and/or frequency resources for a PRACH preamble transmission. FIG.16 illustrates a frequency resources selection method for a PRACHtransmission of a regular device or UE.

Since the supported BW for devices described herein such as MTC devicesor UEs may be narrower than the system (e.g. LTE or E-UTRAN BW), someconfigured PRACH frequency resources may not be visible and thus notavailable to such devices. For example, as shown in FIG. 17 showsdevices such as MTC devices or UEs that may support a 5 MHz BW may haveless frequency resources allocation available than the regular UE (e.g.shown in FIG. 16) when their supported BW may not equal to that ofsystem (e.g. LTE or E-UTRAN).

Additionally, a Random Access (RA) response to the UE may be providedvia MAC layer signaling that may be transmitted in PDSCH. According toan example embodiment, a location of the PDSCH may be identified by aPDCCH (e.g. with RA-RNTI for a contention-based procedure) in the commonsearch space in the PDCCH. In one embodiment, the PDCCH may be spreadover the entire bandwidth (BW) of the cell. As such, narrower bandwidthdevices such as UE or MTC devices may not decode the PDCCH as describedabove and the RA procedure may not be completed. As such, the system andmethods disclosed herein may enable devices such as UE or MTC devicesoperating on reduced BW to receive a RA response.

Broadcast problems and/or issues may be incurred by the use of a BWreduction and/or the devices that support the BW reduction. For example,a narrower bandwidth device such as a UE and/or MTC device may not haveaccess to the whole system bandwidth, and, thus, as described herein,the device may not be able to detect a PDCCH grant when a part of suchgrant may be located outside of the narrower bandwidth. As such, thedevice may not be able to determine the resources assigned to broadcastSIBs and may not be able to receive the broadcast SIBs. Systems and/ormethods described herein may enable such devices (e.g. narrow bandwidthdevices) and networks to determine resources to broadcast SIBs andreceive broadcast SIBs.

In embodiments, paging problems and/or issues may be incurred with a BWReduction as described herein. For example, a narrower bandwidth devicesuch as a UE or MTC device may not have access to the whole systembandwidth, and, thus as described herein, the device may not be able todetect a PDCCH grant when a part of such grant maybe located outside ofthe narrower bandwidth. As such, the device may not be able to receivepages for reading PDCCH and/or the paging channel. In an exampleembodiment, systems and/or methods described herein may enable suchdevices (e.g. narrow bandwidth devices) and networks to receive suchpages.

According to an example embodiment, the use of such narrower bandwidthor lower bandwidth devices may reduce a transceiver complexity (e.g. theuse of such devices may enable a lower complexity of transceivers). Forexample, the throughput requirements for devices such as UEs or MTCdevices that support a reduced BW may be relatively low when comparedwith legacy LTE UEs or other legacy devices (e.g. even with the lowestUE category). In an embodiment, an application for a device such as aMTC device (e.g. with a narrower bandwidth) may be a smart meteringrequiring status update. Current or legacy devices may be required toimplement each transmission modes and its associated reporting modesregardless of the UE category to provide robust transmission accordingto the UE channel condition and system environment. If the samerequirement may be applied for the UE category targeted for low cost MTCdevice, it may result in unnecessary transceiver implementationcomplexity and/or increased costs.

As described above, the typical application of a low cost MTC device maybe a smart meter operated with a battery. In such an embodiment, thesmart meter may use a longer lasting battery life as compared with astandard or regular device such as a UE or handset and/or laptop thatmay be charged frequently. Unfortunately, current device behavior thatmake invoke TTI-based control channel blind detection and/or a 8 HARQprocess or method may result in faster batter consumption and, thus, maynot work well with such lower powered devices such as MTC devices orUEs.

Additionally, UE categories may be equipped with at least two receiveantennas (e.g. which may be mandatory) such that the network coveragemay be defined based on the assumption of two receive RF chains. Toreduce the cost of device such as a UE or MTC device, a single receiveRF chain based UE category may be defined, thus resulting in coveragereduction in the downlink. Because the device such as the UE or MTCdevice may also work with legacy UEs (e.g. Rel-8/9/10), the coverage maybe kept the same as other networks such as a previous LTE network to notincrease network deployment cost while supporting low cost devices suchas UEs or MTC devices in the same network.

MTC physical uplink control channel (PUCCH) transmissions may also beprovided and/or used. For example, when operating a device such as a UEor MTC device that may support a smaller or reduced bandwidth on achannel such as a regular LTE channel or bandwidth, in an embodiment, aPUCCH region for such a device such as a MTC device or UE may overlapwith a sounding reference signal (SRS) bandwidth for a legacy UE. Insuch an embodiment, there may be a possibility that a PUCCH transmissionfrom a device such as a UE or MTC device may overlap with the legacy SRSregion. As such, techniques may be provided and/or used to handle such asituation.

For example, systems and/or methods for low cost devices such as UEsand/or MTC devices to support operation at reduced channel bandwidth ina network such as LTE network may be described herein. In an embodiment,reducing the supported channel bandwidth may reduce theanalog-to-digital and digital-to-analog interface complexity and powerconsumption, as well as the baseband component processing complexity asdescribed herein.

Additionally, control channels in a reduced bandwidth may be providedand/or used as described herein. For example, in one embodiment, alow-complexity device such as a UE or MTC device may receive an inbandDL assignment that may identify an intended receiver of a PDSCHtransmission through inband signaling that may be carried in a DataRegion of a subframe. The inband DL assignment that may identify theintended receiver of the PDSCH transmission may be accompanied byinformation describing the specifics of the transmission such as amodulation type, a coding rate, RV, a number of transport blocks,antenna encoding formats or transmission schemes, and the like.

In a further embodiment, a device (e.g. a low-cost device that maysupport a reduced bandwidth) such as a UE or MTC device may receive aninband UL grant for an upcoming PUSCH transmission as part of thesignaling that may be carried in the Data Region of a subframe. Theinband UL grant may identify the intended transmitter to which the PUSCHtransmission may have been assigned. Similarly, the inband UL grant maybe accompanied by information describing the specifics of the upcomingUL transmission opportunity such as the modulation type, coding rate,RV, a number of transport blocks, antenna encoding formats ortransmission schemes, and the like.

As described herein, multiple devices (e.g. low-cost devices that maysupport a reduced bandwidth) such as UEs or MTC devices may be assignedto monitor the inband signaling carried in the Data Region of thesubframe. Additionally, the DL PDSCH and UL PUSCH transmission resourcesmay be assigned independently from each other in every schedulinginstance, or TTI, amongst these multiple devices. For example, a firstdevice such as a first MTC device may be allocated the DL PDSCHtransmission through the inband signaling while a second device such asa second MTC device may be allocated the accompanying or associated ULPUSCH transmission opportunity in this inband signaling message.

In example embodiments, the inband signaling that may be carried on themonitored parts of the Data Region by the MTC devices refers tomultiplexing the signaling information with a DL data unit or controldata unit as part of the PDSCH transmission resources in an FDM and/orTDM fashion onto available RE's or modulation symbols (and by extension,onto symbols and RB's). It can also refer to carrying the inbandsignaling multiplexed with the DL data unit(s) or control data unit(s)as part of (or separately inserted) RLC or MAC or L1 header informationwhen transport blocks are made available for transmission by the eNB.

Additionally, in an embodiment, a device such as a UE or MTC device, forexample, after acquiring a cell such as an LTE cell or synchronizing tothe cell such as the LTE cell, acquiring system information, and/orregistering to the network, may be subsequently assigned to monitorspecific bandwidth parts of the overall system bandwidth for occurrencesof DL allocations and/or UL grants. Similarly, as described herein,methods or procedures to allocate or de-allocate a set of monitoredresources to MTC devices to monitor for occurrences for DL inbandsignaling may be provided and/or used.

The following illustrative methods or procedures and examples maydescribe the above methods in more detail. While the figures illustrateaspects of some of the embodiments using an example of an LTE channel atnominal BW of 10 MHz, and an MTC device supporting up to 5 MHz reducedBW, these methods and systems described herein extend to the generalcase where a device such as a UE or MTC device that may support lessthan the nominal BW of the cell is in communication with a network suchas the LTE network.

Additionally, embodiments may enable a device such as UE or MTC devicesto not use a legacy LTE PDCCH signal sent over the entire systembandwidth. For example, DL assignments and/or UL grants may be monitoredand carried inband on a DL channel in the Data Region of a subframe suchas a LTE subframe (e.g. the PDSCH) or the time and/or frequency regioncorresponding to DL data transmissions. As such, the device such as theUE or MTC device may support a reduced reception bandwidth, for example,5 MHz, and the like while being able to operate on a channel such as anLTE channel of, for example, 10 MHz, or the that may simultaneouslyoperate using high data-rates or legacy devices such as UEs or LTEdevices at full system bandwidth in a fully backwards-compatible manner.

For example, in one embodiment, a device such as a UE or an MTC devicemay monitor one or more RBs on a designated portion of the Data Regionin a subframe such as an LTE subframe for occurrences of inbandsignaling identifying the intended receiver of the DL data transmissionby the eNB as shown in FIG. 18. The device such as a UE or MTC devicemay monitor designated OFDM symbols and/or frequency portions of thetransmitted DL signal. The transmitted DL signal may include or mayencode an inband DL assignment (e.g. shown in the dotted shading in FIG.18). In one embodiment, the DL assignment may be given in a form of anidentifier that may associate a given DL data transmission (e.g. shownin the diagonal shading of FIG. 18) in that subframe on the PDSCHresources with an intended receiver.

For example, the device such as the UE or MTC device that may bedesigned and/or implemented to support up to 5 MHz bandwidth may beassigned by the network such as the LTE network to monitor the PDSCHregion corresponding to a 5*180 kHz=900 kHz wide PDSCH portion in RBs23-27 on the 10 MHz carrier in designated subframes and to decode the DLtransmission and check for occurrences of the designated identifier partof that DL transmission. Both frequency contiguous resources as well asdistributed resource mapping may be used.

The device such as the UE or MTC device may monitor a designated timeand/or frequency resource for occurrences of its identifier. Forexample, the device such as the UE or MTC device may monitor N PRBs ineach 2nd subframe such as shown in FIG. 18. When the device such as theUE or MTC device may decode its assigned identifier (e.g. in dottedshading of FIG. 18), as part of the DL signal transmission, it mayproceed to decode the corresponding data unit or units (e.g. thediagonal shading of FIG. 18) in that subframe. If the decoded identifiermay not correspond to its assigned identifier (and/or the datatransmission may be intended for another receiver), the device such asthe UE or MTC device may discard the demodulated signal and may wait forthe next expected occurrence of a DL transmission.

Additionally, an identifier may be signaled as part of the DL assignmentexplicitly, for example, through a bit field included into the DL signaltransmission, the identifier may be implicitly encoded, for example, viamasking the identifier into the computed CRC of a TB or code block partof the DL signal transmission, and/or the identifier may be encodedthrough applying a scrambling sequence applied to the DL transmissionsor portions thereof as a function of the identifier value. In analternative embodiment, the identifier may be known by the device suchas the UE or MTC device through a pre-arranged transmission schedule(e.g. DL transmissions may correspond to a set of configured or computednumber of TTIs for a device such as a UE or MTC device). Several examplerealizations to encode the identifier as part of the DL transmission onmonitored resources by the MTC devices may be shown in FIG. 19.

In an embodiment, when an inband DL assignment (e.g. parts of or a RLCor MAC or L1 header, identifier, modulation format information asdescribed above) may be mapped to the transmitted DL signal, the mappingof such header information may exploit the unequal error protectionproperty of higher order modulation alphabets and/or the closeness topilot symbols or tones to increase its detection reliability. Forexample, selected parts of or entire header information, including DLassignment, identifiers, system signals for robust performance, and thelike may be first mapped onto transmission resources to the advantageoussymbol and/or bit positions in the resources allocated to that DL datatransmission. Subsequently, the remaining portion of the DL datatransmission, for example, the bits corresponding to the data units, maybe mapped (e.g. in order) to the remaining positions of thetime-frequency resources. The network may configure the device such asthe UE or MTC device to monitor for one or more identifiers.Alternatively, the DL data transmission (e.g. as shown in FIGS. 18 and19, for example, in the diagonal shading) may include more than one dataunit multiplexed as part of the transmission and intended for more thanone designated receiver.

For example, the identifier used by the network to allocate DL resourcesto the device such as the UE or MTC devices may be an assigned N bitvalue (e.g. N=5). As such, in an embodiment, up to 32 data streams (e.g.where one device may be allocated more than one of these data stream),or intended receivers may be distinguished as part of an ongoing DLtransmission. The 5 bit identifier may be signaled as part of a L1header, a MAC, an RLC header field, and the like that may be multiplexedwith the data and mapped to the transmission resources for that PDSCH(e.g. shown in FIGS. 18 and 19 in subframe n+2). In an alternativeembodiment, the identifier may be part of a separate physical signalmapped to the transmission resources that may be assigned to bemonitored by the device such as the UE or MTC device in the allocatedtime and/or frequency resources (e.g. shown in FIG. 18 in subframe n).

Moreover, the network may assign a specifically designated schedule formonitoring of the DL transmissions to a device such as an MTC device.For example, a device such as a UE or MTC device may monitor onedesignated subframe per radio frame or one subframe occurring each 4radio frames for the occurrence of its designated identifier in a DLdata transmission. The DL transmission may be accompanied by informationdescribing the specific encoding, for example, the transmission format.Information about the transmission format may include the modulationtype, coding rate, RV, a number of transport blocks, antenna encodingformats or transmission schemes, and the like. The identifier and/orspecific information pertaining to the transmission format may be sentusing a first known or configured transmission format.

The device such as the UE or MTC device may obtain the specifictransmission format chosen by the eNB for the DL data unit transmissionby decoding transmission format information as part of the DL signaltransmission using one or more fixed transmission formats for thetransmission format information.

Additionally, the data units carried as part of the DL signaltransmission that may be monitored by the device such as the UE or MTCdevice may carry regular data traffic such as unicast HTTP, FTP and thelike or it may control data such as system information messages or partsthereof, paging signals, and the like.

In an example embodiment, a device such as an MTC device or UE maymonitor one or more RBs on a designated portion of the Data Region in asubframe such as an LTE subframe for occurrences of inband signalingidentifying the intended transmitter for an upcoming or scheduled ULdata transmission. The associated UL subframe may be given byassociation such as a fixed rule “UL grant decoded in subframe ncorresponds to the PUSCH transmission in subframe n+k”, or it may beexplicitly signaled as part of the DL signal transmission and associatedtransmission format.

Similarly, the UL transmission may be accompanied by informationdescribing the specific encoding such as the transmission format.Information about the transmission format may include the modulationtype, coding rate, RV, a number of transport blocks, antenna encodingformats or transmission schemes, and the like. The above-describedembodiments that may encode and carry the inband DL assignments orheader information may be used for the UL grants including bit swapping,mapping to high reliability positions, and the like.

A DL signal transmission may include both inband DL assignments and ULgrants, or in a specific occurrence (TTI), one of these. Forillustration purposes, the inband UL grants may be shown in FIG. 20 forthe embodiment where both DL assignments and UL grants may be part ofthe DL signal transmission to devices such as UEs or MTC devices. Thedevice such as a UE or MTC device may monitor a designated time and/orfrequency resource for occurrences of its UL identifier. For example,the device such as a UE or MTC device may monitor N PRBs in each 2ndsubframe such as shown in FIG. 20. When the device such as a UE or MTCdevice may decode its assigned UL identifier as part of the DL signaltransmission, it may proceed to prepare for UL transmission of a dataunit or units in the associated UL transmission resources in anassociated UL subframe. If the decoded UL identifier may not correspondto its assigned UL identifier (e.g. and the UL transmission may bescheduled for another MTC device), the device such as the UE or MTCdevice may disregard this UL grant and may wait for the next expectedoccurrence of a DL transmission.

According to an embodiment, a UL identifier may be signaled as part ofthe DL assignment explicitly through a bit field included into the DLsignal transmission. Additionally, the identifier may be implicitlyencoded via, for example, masking the identifier into the computed CRCof a TB or code block part of the DL signal transmission or theidentifier may be encoded through applying a scrambling sequence appliedto the DL transmissions or portions thereof as a function of theidentifier value. In an embodiment, the UL identifier may be known bythe device such as a UE or MTC device through a pre-arrangedtransmission schedule or UL transmissions that may correspond to a setof configured or computed number of TTIs for the device such as a UE orMTC device. Additionally, the network may configure the MTC device tomonitor for one or more UL identifiers. The data units to be transmittedas part of the scheduled UL PUSCH transmission may also carry regulardata traffic such as unicast HTTP, FTP and the like, or they may controldata such as system messages or parts thereof including RRC or NASsignaling messages. While a method to signal DL assignments and a methodto signal UL transmission grants have been described above, such methodsmay further be employed to operate in conjunction, separately, or withadditional methods.

According to another embodiment, a device such as a UE or MTC device maybe configured by an eNB or network node such as an LTE network node tomonitor specific bandwidth parts of the overall system bandwidth. Suchmonitored occurrences may include inband DL allocations and/or UL grantsin the form of identifiers and/or transmission formats. For example, adevice such as a UE or MTC device that may support a reduced BW maysynchronize in the DL to a cell such as an LTE cell that may support ahigher BW. For example, the device such as a UE or MTC devices mayacquire the DL synchronization signals and PBCH/MIB broadcast by thecell such as the LTE cell. Such signals may be carried in the center 6RBs of the cell such as the LTE cell and may already serve the purposeto allow configuration of system parameters including system bandwidthin the R8 system. The device such as a UE or MTC device may decodesystem information pertaining to random access such as given throughSIB1 and/or SIB2 in the network or system such as the LTE system throughmonitoring pre-determined occurrences of system information sent in acenter bandwidth in designated subframes and bandwidth portions, thenmay register to the network via a random access procedure.

As part of or following the registration with the network, the devicesuch as a UE or MTC device may be configured with designated DLtransmission resources to be monitored. Additionally, DL and/or ULidentifiers when signaled inband on these monitored resources may enableor allow the device to receive DL data transmissions or when receivedmay allow the device to transmit UL data transmissions.

A similar procedure or method may be used for a device such as a UE orMTC device when already registered with the network such as the LTEnetwork to either change the allocated DL transmission resources to bemonitored (e.g. in terms of an allocated identifier, a transmissionformat, a schedule, and the like).

A device such as a UE or MTC device that may monitor allocated DLtransmission resources on the monitored time and/or frequency resourcesmay determine if at least one DL identifier signaled inband as part ofthe DL transmission resources may be received. The device such as a UEor MTC device may determine if at least one received DL identifier maycorrespond to its own identifier, and if so, may proceed to decode thecorresponding DL data transmission in that subframe. Otherwise, it mayreturn to monitoring. In addition, or independent from the monitoredoccurrences for the DL identifiers, the device such as a UE or MTCdevice may attempt to decode the DL signal transmission resources forpresence of at least one UL identifier. If it may receive and validatesat least one UL identifier, the device such as a UE or MTC device mayprepare for transmission, then may transmit the UL PUSCH in theassociated and designated UL transmission resource.

According to the methods described herein, the network such as a LTEnetwork may allocate devices such as UEs or MTC devices using a flexiblereception schedule, and it may allocate both DL and UL transmissionresources to MTC devices in a flexible manner even in presence of legacyor high data rate devices such as LTE devices supporting the fullnominal bandwidth of the cell. In particular, the network such as a LTEnetwork may allocate more than one device such as a UE or MTC device tomonitor the same DL transmission resource for scheduled DL datatransmissions. Given typically small data rates (e.g. order of 10's or100 kbps) for such devices such as UEs or MTC devices, spectrumefficiency may be achieved by having the ability to dynamicallymultiplex device data such as MTC for a population of devices such asUEs or MTC devices in a dynamic network-controlled scheduling process.

The multiple access approach described by the methods herein may beshown in FIG. 20. According to an example embodiment, the rule chosenfor such an embodiment may include that a UL grant in subframe n maycorrespond to a PUSCH transmission in subframe n+4. Additionally, afirst set of devices such as UEs or MTC devices may be allocated tomonitor PDSCH transmission resources in subframe 1, and once per frame.A second set of devices such as UEs or MTC devices may monitor subframe1, but another set of designated DL transmission resources every otherframe. A third set MTC devices may also monitor subframe 2 and each 2ndframe for DL signal transmissions. The eNB may further dynamicallyallocate DL transmissions and UL transmissions within the individualgroups of monitoring devices such as UEs or MTC devices.

In some embodiments, devices such as UEs or MTC devices may implementsupport for processing a reduced channel bandwidth with dramaticconsequences and reduction onto RF component cost and count and/orscaled down ADC/DAC and BB processing capabilities when compared todevices such as LTE devices supporting full nominal bandwidth, (e.g. upto 10 or 20 MHz).

Control information signaling in PDSCH (e.g. data) regions may also beprovided and/or used with devices such as UEs or MTC devices that may belower-cost and/or may support a reduced bandwidth. For example, in otherembodiments, a device such as a UE or MTC device may receive downlinkcontrol channels in the PDSCH region with the limited bandwidth support.The device such as the UE or MTC device may receive the downlink controlchannels in the PDSCH region since the legacy downlink control channelsmay be at least partially readable.

Additionally, a Physical Control Format Indicator Channel (PCFICH)indication may be provided and/or used as described herein. For example,the PDCCH and PDSCH such as the LTE PDCCH and PDSCH may be multiplexedusing TDM in a subframe and the boundary between the PDCCH and PDSCH maybe indicated by PCFICH in each subframe. As such, to transmit downlinkcontrol channels in the PDSCH region, the device such as the UEs or MTCdevices may be informed of the boundary.

The device such as the UEs or MTC devices may receive the boundaryinformation of PDCCH and PDSCH region using one of the followmechanisms. For example, to receive such information, higher-layersignaling may be provided and/or used where UE-specific RRC signalingmay indicate the boundary of PDCCH and PDSCH in the subframes. Theboundary information may be valid to a subset of subframes in a radioframe, a subset of radio frames, and/or a subset of subframes inmultiple radio frames (e.g. four radio frames). In such embodiment, thedevice such as a UE or a MTC device and/or group may have differentsubsets of subframes and/or radio frames such that the PCFICH value mayvary from a subframe to another from eNB perspective. In embodiments,this may provide higher system throughput.

Additionally, to receive such boundary information, broadcastinginformation may provided and/or used. For example, the PCFICH value forMTC devices is informed in broadcasting channel (e.g., SIB-2).

In another embodiment, to receive such boundary information, a newPCFICH (e.g. a M-PCFICH) may be transmitted for devices such as UEs orMTC devices in the PDSCH region. For example, a device such as a UE orMTC device may receive an M-PCFICH in a subframe n-k which may be validin the subframe n. The value k may be a fixed positive integer valuesuch as ‘1’ or ‘2’ or variable according to the higher signaling. The kmay be ‘0’ as a fixed value.

Furthermore, to receive such boundary information, a radio frame headermay be provided and/or used. For example, a radio frame header that mayindicate the PCFICH for subframes in a radio frame (e.g. 10 ms) may betransmitted. A radio frame may include a single PCFICH that may be validfor subframes or multiple PCFICH values for each subframe or group ofsubframes in a radio frame. In embodiments, the radio frame may belonger than 10 ms such as 40 ms, and the like. The radio frame headermay also be transmitted in the first subframe in a radio frame.

According to another embodiment, a PCFICH may not be used by narrower BWdevices such as UEs or MTC devices. For example, PDSCH intended fordevices such as UEs or MTC devices may start in a specific symbol of asubframe that may be known to the devices regardless of the actualboundary between PDCCH and PDSCH indicated by PCFICH. In such anembodiment, for the narrower BW device such as UEs or MTC devicesoperating in a cell with a larger BW, the PDSCH may be allocated as ifPDCCH region was always a fixed number of symbols (e.g. 3 symbols).

Such an embodiment may also be applicable to the use of ePDCCH byparticular devices such as reduced BW UE or MTC devices. For example,the ePDCCH that may be intended for such devices may start in a specificsymbol of a subframe that may be known to the particular devicesregardless of the actual boundary between the PDCCH and PDSCH that maybe indicated by the PCFICH. In such an embodiment, for devices operatingin a cell with a larger BW, the ePDCCH may be allocated as if the PDCCHregion may be a fixed number of symbols (e.g. 3 symbols).

According to example embodiments, a device such as UE or MTC device mayreceive the M-PCFICH in the positions of the zero-power CSI-RS orsubsets of configured zero-power CSI-RS. The use of zero-power CSI-RSfor a M-PCFICH transmission may enable the impact of legacy UEs (e.g.LTE Rel-10 UEs) to be avoided or limited as such legacy UE rate-matchthe zero-power CSI-RS while exploiting frequency diversity gain. The 10zero-power CSI-RS configurations that may be available (e.g. in Rel-10)for FDD and may be used herein may be shown in the table of FIG. 22 andthe zero-power CSI-RS patterns according to the CSI reference signalconfiguration number that may be used herein may be shown in FIG. 23.

Additionally, in embodiments, a single or multiple zero-power CSI-RS(s)may be configured in a subframe with a duty cycle. As such, a M-PCFICHtransmission may include a duty cycle. For the duty cycle based M-PCFICHtransmission, a device such as a UE or MTC device may receive theboundary information of PDCCH and PDSCH for subframes within duty cycleswith one of following: M-PCFICH bundling within a duty cycle, individualM-PCICH transmission, and the like.

In M-PCFICH bundling within a duty cycle, an M-PCFICH value may be validwithin duty cycle such that device such as a UE or MTC device mayconsider the same PCFICH value for multiple subframes within a dutycycle. For example, if a M-PCFICH duty cycle may be configured with K msand an M-PCFICH may be received in subframe n, the M-PCFICH value may bevalid until the subframe n+K−1. The M-PCFICH starting subframe may alsobe defined with an offset. In such an embodiment, the M-PCFICH value mayvalid between subframe n+Noffset and n+K−1+Noffset. An example Noffsetmay be “1.”

In an individual M-PCFICH transmission, multiple M-PCFICH values may betransmitted in the subframe which may inform or provide a PCFICH valuefor each subframe or multiple groups of subframe in the duty cycle.

Various zero-power CSI-RS configurations and associated M-PCFICHtransmission schemes may be provided and/or used herein. For example, inone embodiment (e.g. a first example), a single zero-power CSI-RS may beconfigured for M-PCFICH transmission. The single zero-power CSI-RSconfiguration may include a CSI-RS pattern among 4 CSI-RS ports patternsand a duty cycle with a subframe offset. Additionally, four REs may bereserved in a PRB-pair for zero-power CSI-RS.

In such an embodiment, a device such as a UE or MTC device may receivethe M-PCFICH in the zero-power CSI-RS REs based on one or more offollowing: a CRS-based transmission scheme, a sequence basedtransmission, a DM-RS based transmission, and the like. According to anexample embodiment, the CRS-based transmission scheme may be dependenton or based on the number of antenna ports such as Port-{0} in a singleCRS port, Port-{0, 1} in two CRS ports with a time domain space timeblock code (STBC) in the position of zero-power CSI-RS in which a pairof STBCs may be transmitted in the time domain consecutive REs (e.g. aOCC RE pair), a Port-{0, 1, 2, 3} in four CRS ports with a STBC combinedwith frequency switched transmit diversity (FSTD) in which a pair ofSTBCs may be transmitted in an OCC RE pair through Port-{0, 2} and theother pair of STBCs may be transmitted in another OCC RE pair throughPort-{1, 3}.

Additionally, the sequence based transmission may include orthogonal orquasi-orthogonal multiple sequences that may be defined and transmittedin the position of zero-power CSI-RS RE. According to the sequencenumber, a device such as a UE or MTC device may notice the boundary ofPDCCH and PDSCH.

In a DM-RS based transmission, a new DM-RS based antenna port may bedefined. The pattern of the new DM-RS port may be located in the firstOFDM symbol in each OCC RE pair. Multiple orthogonal DM-RS ports mayalso be defined and the DM-RS port may be configured by higher layersignaling and/or tied with a physical cell ID.

In another embodiment (e.g. a second example), a pair of zero-powerCSI-RS configuration may be used for M-PCFICH transmission. For example,the configuration {0, 5}, {1, 6}, {2, 7} {3, 8} and {4, 9} may beconfigured together. In such a configuration, a device such as a UE orMTC device may receive the M-PCFICH in the pair of zero-power CSI-RSbased on one or more of following schemes: a CRS-based transmissionscheme, a sequence based transmission, a DM-RS based transmission andthe like as described herein. According to such embodiments, theCRS-based transmission scheme may be dependent upon or based on thenumber of antenna ports such as Port-{0} in a single CRS port, Port-{0,1} in two CRS ports where a time domain space frequency block code(SFBC) may be in the position of zero-power CSI-RS and a pair of SFBCmay be transmitted in the frequency domain consecutive two REs, Port-{0,1, 2, 3} in four CRS ports with SFBC with frequency switched transmitdiversity (FSTD) in which a pair of STBCs may be transmitted in thefrequency domain consecutive two REs through Port-{0, 2} and the otherpair of SFBCs may be transmitted in another two REs in the next OFDMsymbol through Port-{1, 3}.

In the sequence based transmission, orthogonal or quasi-orthogonalmultiple sequences may be defined and transmitted in the position ofzero-power CSI-RS RE. According to the sequence number, a device such aUE or MTC device may notice the boundary of PDCCH and PDSCH.

Additionally, in the DM-RS based transmission, a new DM-RS based antennaport may be defined. The pattern of the new DM-RS port may be one of thetwo zero-power CSI-RS configuration. Multiple orthogonal DM-RS ports mayalso be defined and the DM-RS port may be configured by higher layersignaling and/or tied with a physical cell ID.

An MTC device may receive the PDCCH in the PDSCH region in the secondslot and the resource definition of the downlink control channels forM-PDCCH including PCFICH, PHICH, and PDCCH are the same as the LTE withthe given bandwidth for MTC device. Among the downlink control channels,a subset of control channels may be available in the M-PDCCH region suchas {PCFICH, PDCCH} and {PHICH, PDCCH}. FIG. 23 shows an exampleembodiment of such a M-PDCCH transmission within the first three OFDMsymbols of a second slot in the MTC bandwidth.

The M-PDCCH region definition for the 0th OFDM symbol may be one or moreof the following. In one embodiment, the M-PDCCH resource may not bedefined in the 0th subframe in a radio frame due to the collision ofP-BCH and M-PDCCH. A device such as a UE or MTC device may assume thatno downlink control channel may be available in the 0th subframe.

Additionally, according to an embodiment, the M-PDCCH may be definedwithout the center 6RBs in the 0th subframe. The REG and CCE may bedefined without center 6RBs with rate matching and, thus, the effectiveMTC bandwidth for PDCCH may be smaller in such an embodiment. Forexample, if the MTC bandwidth may be defined as MPRB=25 (e.g. 5 MHz) andthe system bandwidth may be NPRB=50 (e.g. 10 MHz), the PDCCH resourcesuch as the LTE PDCCH resource may be defined based on NPRB=50.Additionally, the M-PDCCH resource except for 0th OFDM symbol is definedbased on MPRB=25 and the M-PDCCH resource for 0th OFDM symbol may bedefined based on MPRB=19 (i.e., 25-6). Such an embodiment or method mayenable or allow the scheduling flexibility using dynamic resourceallocation from an uplink and/or downlink grant in each subframe. On theother hand, the M-PDCCH resource allocation in the MTC bandwidth in anavailable subframe may cause a legacy performance impact due to thecollision between M-PDCCH and legacy PDSCH (e.g. because the legacy UEsuch as legacy LTE UE may not notice the existence of a M-PDCCH).

In another embodiment (e.g. a second method), a M-PDCCH resource may beflexibly allocated in the M-PDCCH region to minimize the legacy impactsuch as an LTE UE performance impact due to the collision between thelegacy PDSCH and M-PDCCH. For such an embodiment or method, the M-PDCCHresource may be defined with one of the following.

The bandwidth of the M-PDCCH may be reduced to an amount even smallerthan the device BW such as the MTC BW. For example, although the MTCbandwidth may be MPRB=25, the number of PRBs for the device BW or MTC BWmay be independently defined with MPRB, PDCCH which may be equal to orsmaller than MPRB. The MPRB, PDCCH may be provided, indicated, orsignaled via higher layer signaling or broadcasting channels.

Additionally, the available subframe for M-PDCCH resource allocation maybe restricted to a subset of the subframes in a radio frame or multipleradio frames. The subframe subset for M-PDCCH resource allocation may bepredefined as {4, 5, 9} subframes or {0, 4, 5, 9} subframes. Thesubframe subset for M-PDCCH resource allocation may be configured inhigher layer with a duty cycle such as 10 ms and 40 ms. The subframethat may include a M-PDCCH resource may be implicitly indicated by oneor more of the following: if a subframe may include a CRS in the legacyPDSCH region, if M-PDCCH region is not collide with non-zero powerCSI-RS, and the like.

The subframe subset which may be allowed for M-PDCCH may also bedefined. For example, the subframe subset such as {0, 4, 5, 9} or {4, 5,9} may be used and/or defined as a fixed subset. The subframe subset maybe defined by higher layer signaling with 10 ms or 40 ms duty cycles.Additionally, the subframe subset may be implicitly defined as thesubframe including a CRS in the legacy PDSCH region.

In another embodiment (e.g. a third method), zero-power CSI-RS resourcesmay be used. For example, the REG definition for a M-PDCCH may be thefrequency domain four consecutive zero-power CSI-RS REs. FIG. 25 depictsan example where possible CSI-RS patterns may be configured aszero-power CSI-RS in a subframe. For example, nine REGs may be definedwithin a PRB such that 9×MPRB may be the available REGs in the subframeif the 4Tx CSI-RS patterns may be configured for zero-power CSI-RS. Inan embodiment, although the 4Tx CSI-RS patterns may be configured forthe zero-power CSI-RS, the subframe of the configured zero-power CSI-RSmay be used for M-PDCCH resource allocation.

In such an embodiment or method, the zero-power CSI-RS may be configuredwith a duty cycle such that the M-PDCCH resource allocation may bepossible each Nduty [ms] where Nduty may imply the duty cycle for thezero-power CSI-RS configuration for the M-PDCCH. According to an exampleembodiment, such a method may be backward compatible for legacy UEs suchas LTE UEs (e.g. Rel-10 UEs) since the position of the zero-power CSI-RSmay be rate-matched.

In still further embodiments, methods for signaling in a PDCCH (e.g.control) region may be provided to enable or allow a device such as a UEor MTC device to receive downlink control channels in the PDCCH regionwith the limited bandwidth readability. To reuse the current downlinkcontrol channels such as LTE downlink control channels, the device suchas the UE or MTC device may be informed of or provided the parametersrelated to the legacy downlink control channels including the totalnumber of PRBs and PHICH configurations.

Additionally, a device such as the UE or MTC device may receive a PCFICHas described herein. For example, the device may receive the PCFICH inthe RE position of legacy PCFICH. Since a device may detect a subset ofREGs for a PCFICH, PCFICH bundling in which a device may assume thatconsecutive multiple subframes may indicate the same CFI value may beused. According to an example embodiment, in PCFICH bundling, similarPCFICH coverage may be achieved from time domain bundling. Such timedomain bundling may use, provide, and/or exploit time diversity gain.Additionally, in such an embodiment, among the sets of 4 REGs forPCFICH, the readable REGs may be 1, 2, 3, or 4 according to the systembandwidth. If the REGs (e.g. the 4 REGs) may be within the device, UE orMTC supportable bandwidth, the PCFICH bundling may not used and thedevice behavior may be the same as the legacy device such as LTE UEs.

For PCFICH bundling, the number of subframe for that may be used and/orprovided may be defined. For example, in one embodiment, the number ofsubframe for PCFICH bundling (Nsubframe) may be defined according to thenumber of REGs within the MTC supportable bandwidth using, for example,

$N_{subframe} = {\left\lceil \frac{4 - M_{REG}}{2} \right\rceil + 1}$

where MREG may denote the number of available REG for PCFICH in thesupportable bandwidth such as device or UE or MTC supported bandwidth,Nsubframe=4 if one REG may be available, Nsubframe=2 if two REGs may beavailable, Nsubframe=2 if three REGs may be available, and the like.

Additionally, the CFI codeword for each case may be defined with asubset of codeword associated with the rest of REGs for PCFICH shown inthe table of FIG. 26. For example, if two REGs may be readable in thesupportable device bandwidth and the first and the last REGs may belocated out of the device bandwidth, the CFI codeword that may be usedmay be shown as the table of FIG. 26. As another example, if the secondREG may be available in the device supportable bandwidth, the CFIcodeword that may be used may be shown in the table of FIG. 27.According to an example embodiment, such a method may enable or allow abackward compatible PCFICH transmission while keeping similar coveragefor a device such as a UE or MTC device.

In an embodiment (e.g. for PHICH reception), a device such as a UE orMTC device may receive a PHICH in the RE position of a legacy PHICH. Toreceive a PHICH, 3 REGs may be received in a subframe. The number of REGreadable in the device supportable bandwidth may be different accordingto the system bandwidth and device supportable bandwidth. For example,if 3 REGs for a PHICH may be readable, the device PHICH receptionbehavior may be the same as that of legacy device such as a LTE UE.However, if one or two REGs for PHICH may be available, a PHICH may bereceived by a device using one or more the following methods.

For PHICH group bundling, if one REG may be readable in the devicesupportable bandwidth, three consecutive PHICH groups may be bundledtogether to indicate a PHICH. As an example, a PHICH group 1, 2, and 3(e.g. as shown in FIGS. 9 and 15) may be bundled and the 1st PHICHgroup, 2nd PHICH group, and 3rd PHICH group may be considered a 1st REG,2nd REG, and 3rd REG respectively.

For reduced repetition coding, if two REGs may readable in the devicesupportable bandwidth, the HARQ may be redefined as follows. A HARQindicator (HI) may be a 2-bit HARQ indicator that may be defined for 2REG-based PHICH channel for a device such as a UE or MTC device as shownin FIG. 28 and channel coding for the HI may be provided and/or definedas shown in FIG. 29.

In example embodiments, for PDCCH reception, a device such as a UE orMTC device may receive the PDCCH using the same definition of CCE forthe legacy UEs performing in the wider system bandwidth. A CCE mayinclude 9 REGs and the 9 REGs may be distributed in the system bandwidthwith a subblock interleaver. A device such as a UE or MTC device mayreceive a PDCCH in the UE-specific search space and the starting CCEnumber for CCE aggregation may be defined according to one or more offollowing: higher-layer signaling; a RNTI based hashing function; CCEaggregation; and the like.

For blind decoding for PDCCH with CCE aggregation, if the number of REGsreadable in a CCE among the CCE blind decoding candidate may be lessthan a threshold (e.g. 5 REGs), a device such as a UE or MTC device mayavoid a blind decoding trial. The threshold (e.g. Nthreshom) may bedefined as a fixed value or configured in the higher layer signaling.Also, the blind decode dropping for a PDCCH may be defined with theratio in the aggregated CCE candidates. For example, if the percentageof non-readable REGs may be higher than x-% (e.g. x=50), a device suchas a UE or MTC device may drop blind decoding trials. Such an embodimentmay be expressed as follows:

${\frac{{Non\_ readable}\mspace{14mu} {REGs}}{{Total}\mspace{14mu} {REGs}} \geq \alpha_{threshold}},{{{where}\mspace{14mu} 1} > \alpha_{threshold} > 0}$

where the α_(threshold) (e.g. 0.5) may be defined as a fixed vale orconfigured via higher layer signaling.

As described herein, data channels for use with a reduced bandwidthincluding devices that may support a reduced bandwidth may be provided.For example, systems and/or methods for increasing the resourceutilization for the reduced bandwidth support for the PDSCH transmissionin wider system bandwidth may be provided and/or used. In one embodiment(e.g. for illustrative purposes), the supportable bandwidth may be 6resource blocks (RBs) and the system bandwidth may be 50 RBs (10 MHz).Such an embodiment may be illustrative and the systems and/or methodsdescribed may be applied to other supportable reduced BWs and othersystem BWs.

In embodiments, the location of the supportable BW (e.g. 6RBs) for adevice such as a UE or MTC device may be defined as at least one of thefollowing: frequency locations for devices such as a UE or MTC devicesthat may be defined as center RBs (e.g. 6 RBs); a frequency location foreach device that may be in different frequency locations, and thelocation for a specific device may be fixed; frequency locations foreach device may be in different frequency locations and the location fora specific device may be configurable dynamically and/orsemi-statically; and the like. In an embodiment (e.g. for illustrativepurposes), the 6RBs may be a maximum supportable bandwidth for a device;however, the supportable BW may not be limited to the 6RBs. The 6RBs maybe replaced by any number of RBs, which may or may not be fixed innumber, and may still be consistent.

As described herein, a fixed band location may be provided and/or used.For example, in an example embodiment or method, devices may assume thatPDSCH transmissions may be within the center 6RBs in which primarysynchronization signal (PSS)/secondary synchronization signal (SSS) andphysical broadcast channel (PBCH) may be transmitted in a specificdownlink subframe number. In such an embodiment, to minimize blinddecoding complexity, a device such as a UE or MTC device may use atleast one of following assumptions.

For example, in one example assumption, the device such as a UE or MTCdevice may use, provide, and/or assume that a subset of downlinksubframes, (e.g. only a subset) may include PDSCH for the device. Thesubset of downlink subframes for a specific device may be defined by atleast one of following definitions. In one example definition, a validsubframe for PDSCH may be implicitly defined by C-RNTI. For example, amodulo operation may be used with a modulo number Nsub, where the Nsubmay be configured by higher layer signaling, broadcasting, and/orpredefined number. As the Nsub may become larger, the schedulingopportunity for a device may get reduced. In another example definition,the valid subframe for PDSCH may be explicitly signaled by higher layersignaling such as UE-specific RRC signaling.

Additionally, in another example assumption, if a subframe may includePSS/SSS and/or a PBCH, a device such as a UE or MTC device may skipblind decoding for the downlink control indicators (DCIs) related toPDSCH transmission. According to an embodiment, if ePDCCH may be used,ePDCCH resource configuration may be informed in the broadcastingchannels.

In another example embodiment or method, the frequency location for adevice such as a UE or MTC device may be informed by the broadcastingchannel. As such, once a device finishes broadcasting channel receptionsuch as a master information block (MIB) and/or system information block(SIB-x), the device may know which 6RBs may be used. Additionally, sincethe network may avoid center 6RB allocation, the scheduling restrictionin a specific subframe such as subframe #0 and #5 may be relaxed. In anembodiment, the same resources may be shared with each of the devices asin the first method. As such, blind decoding complexity reductionmethods may be used.

In one reduction method, a subset of downlink subframes (e.g. only asubset) may include a PDSCH for the device. The subset of downlinksubframes for a specific device may be defined by at least one offollowing definitions. In one definition, the valid subframe for PDSCHmay be implicitly defined by a cell-radio network temporary identifier(C-RNTI). For example, a modulo operation may be used with a modulonumber Nsub, where the Nsub may be configured by higher layer signaling,broadcasting, and/or a predefined number. As the Nsub may become larger,the scheduling opportunity for a device may get reduced. In anotherexample definition, the valid subframe for PDSCH may be explicitlysignaled by higher layer signaling such as UE-specific RRC signaling.

In another reduction method, if a subframe may include PSS/SSS and/orPBCH, a device such as a UE or MTC may skip blind decoding for the DCIsrelated to PDSCH transmission. Additionally, in an additional reductionmethod, if a subframe may include paging or broadcast SIBs that thedevice may read, the device may skip looking for other requests such asUL and downlink (DL) grants.

As described herein, a flexible band location may be provided and/orused. For example, in an example flexible band location method, afrequency location for a device such as a UE or MTC device may beconfigured in an UE-specific manner and the location may be static orsemi-static so that different frequency locations may be used fordifferent devices which may increase downlink resource utilization andmay relax downlink scheduling restriction. The UE-specific frequencylocation may be configured with at least one of following methods: aRACH msg2 may include a frequency location for a specific UE or device,and, thus, a UE or device may receive PDSCH after RACH procedures;and/or UE-specific radio resource control (RRC) signaling may be used toinform the frequency location. In such an embodiment, a UE or device maywait until it may receive the frequency location for PDSCH reception.

In another example flexible band location method, a frequency locationfor UE or devices may be dynamically allocated via physical controlchannel (e.g. PDCCH, ePDCCH). As such, the reduced bandwidth locationmay be changed from one subframe to another. For such a method, at leastone of the following procedures or methods may be used for frequencylocation configuration. For example, a DCI transmitted via PDCCH mayinclude frequency locations for devices and may be monitored in a commonsearch space. The cyclic redundancy check (CRC) may be masked with a MTCspecific group RNTI. The frequency location, which may be indicated inthe PDCCH may be valid in the same subframe. Additionally, a DCItransmitted via ePDCCH may include frequency locations for devices andmay be monitored in predefined time frequency locations in a subframe.The CRC may be masked with a device specific group RNTI and thefrequency location which may be indicated in the ePDCCH may be valid forone or more subframe(s).

In another example flexible band location method, the frequency locationfor a MTC device may be dynamically allocated via PDCCH. Therefore, theresource allocation in the PDCCH may inform the frequency location. ADCI transmitted via PDCCH may include the frequency location with theresource allocation information within the supportable bandwidth (e.g.6RBs). For example, if Nalloc bits may be used for resource allocationwith full system bandwidth, a subset of Nalloc bits may be used forresource allocation of reduced bandwidth and the rest may be used toindicate the frequency location. As another example, two resourceallocation bit fields may be defined for frequency location and PDSCHresource allocation where the resource allocation method for frequencylocation may be a resource allocation type 2 (e.g. contiguous resourceallocation) and the PDSCH resource allocation may be resource allocationtype 0 and/or 1.

In another example flexible band location method, the frequency locationfor a device such as a UE or MTC device may be dynamically changedaccording to a hopping pattern such that downlink control signalingoverhead may be minimized and inter-cell interference may be randomizedat the same time. The hopping pattern may be defined using at least oneof following: multiple hopping patterns may be predefined and one ofthem may be selected per UE as a function of C-RNTI; hopping patternsper subframe may be defined as a hashing function with parametersincluding, for example, C-RNTI, Cell-ID, Physical Cell Identifier (PCI),subframe number or system frame number (SFN), and the like; and/or anyother suitable mechanisms to define the hopping pattern. In embodiments,frequency location may be replaced by frequency locations, for example,in the case that the locations of the PDSCH RBs that may be intended fora certain or particular UE or device may not be consecutive.

As described herein, band location, ePDCCH, and PDSCH may be providedand/or used. For example, a device such as a UE or MTC device maymonitor and/or attempt to decode both an ePDCCH and a PDSCH in the samesubframe. The ePDCCH may include a UE-specific search space and/orcommon search space. When describing ePDCCH herein, embodiments orexamples involving ePDCCH, ePDCCH common search space and ePDCCHUE-specific search space may be treated the same or differently. Forexample, when referring to ePDCCH, it may mean ePDCCH common searchspace or ePDCCH UE-specific search space, or both. Additionally, a PDSCHthat may be indicated by an ePDCCH may include a PDSCH carrying at leastone of downlink shared channel (DL-SCH), broadcast channel (BCH), pagingchannel (PCH), random access (RA) response, or any other type of datathat a PDSCH may carry. Furthermore when describing examples orembodiments related to ePDCCH and PDSCH reception, the BW or the numberof RBs that may be supported by the device such as the UE or MTC devicemay mean the BW or the number of RBs that may be supported by the devicefor the purpose of reception in the PDSCH region of the cell which maybe different from the RF BW it may support and/or the BW or the numberof RBs it may support for reception of the PDCCH region.

The following examples or embodiments may include ways in which ePDCCHmay be defined or configured and methods or procedures in which a devicesuch as a reduced BW UE or MTC device may be configured with, orunderstand, which ePDCCH resources to monitor and/or attempt to decodeFor example, the examples or embodiments disclosed herein may includemethods or procedures in which ePDCCH may be used by or intended for atleast one reduced BW device.

For example, in one embodiment, an eNB or cell may transmit ePDCCH suchas ePDCCH intended for or intended for use by at least one reduced BWdevice such as a reduced BW UE or MTC device in accordance with at leastone of the ways described herein in which an ePDCCH may be defined orconfigured, one of the methods or procedures in which a device may beconfigured to monitor ePDCCH, or one of the methods or procedures adevice may use to understand which ePDCCH resources to monitor. For thecase of the configuration, for example, for a cell, or a device or agroup of devices, the eNB or cell may provide the configuration to oneor more devices via broadcast or dedicated signaling such as RRCsignaling.

Additionally, a device such as a reduced BW UE or MTC device may monitorand/or attempt to decode an ePDCCH (e.g. an ePDCCH intended for orintended for use by at least one reduced BW device) in accordance withat least one of the methods or procedures described herein in whichePDCCH may be defined or configured, one of the methods or procedures inwhich a device may be configured to monitor ePDCCH, or one of themethods or procedures a device may use to understand which ePDCCHresources to monitor. For the case of configuration, a device mayreceive the configuration from an eNB or cell via broadcast or dedicatedsignaling, for example RRC signaling.

In example embodiments, one or more of the following methods orprocedures may be provided, used, and/or applied (e.g. for ePDCCH). Forexample, an ePDCCH may be defined or configured for a cell, for example,for devices such as devices capable of ePDCCH reception or each of thedevices capable of ePDCCH reception in the cell, where such aconfiguration may be included in signaling such as by RRC signaling andmay be provided via broadcast signaling or dedicated signaling to one ora group of devices. There may be a separate ePDCCH definition orconfiguration for reduced BW devices and for devices supporting the fullcell BW. The ePDCCH resources (e.g. RBs), which may be used by or whichmay be intended for use by certain or particular devices such as reducedBW devices that may be UEs or MTC devices, may be a subset of the ePDCCHresources defined or configured in the cell. The subset may beexplicitly identified by the cell, for example, via broadcast ordedicated signaling. The subset may be derived by the devices themselvesin an embodiment. For example, the subset may be device specific and/ormay be derived by a device based on, for example, at least one of thefollowing: the device IMSI or C-RNTI; a system frame number (SFN); asubframe or timeslot number overall or within a frame; a number ofePDCCH RB groups defined; an ePDCCH hopping pattern; a physical cell ID;a BW supported by the device; a specific set of RBs supported by thedevice (e.g. center X RBs, where X may be for example 6, 12, or 15); theRBs supported by the device as a result of configuration; and the like.

For example, in an embodiment, the ePDCCH may be defined for a cell as Ngroups of RBs in various locations of the full BW. Each of the RB groupsmay include fewer than M RBs (e.g. 5 RBs max). A device such as a UE orMTC device may be configured to monitor one or more of those groups ormay use criteria such as those described above among others to determinewhich group or groups to monitor. A device may also be or may instead beconfigured to monitor a subset of the RBs in a group or may use criteriasuch as those described above or other criteria to determine which RBs,or which RBs in a group or groups to monitor.

If ePDCCH may be defined or configured to include one or more groups ofRBs and for a certain group or groups that the number of RBs may exceeda certain number, the device may exclude certain group or groups fromthe groups it may consider for monitoring. The certain number may be afixed number known to the device, the number of RBs in its supported BW,or certain a value (e.g. one) less than the number of RBs in itssupported BW.

When monitoring ePDCCH in a given subframe, a device such as a reducedBW UE or device (e.g. a MTC device) may assume that the PDSCH intendedfor it may be located in frequency such that the BW the device supportsmay not be exceeded. For example, the RB(s) for PDSCH that may beindicated by the ePDCCH may be located sufficiently close in frequencyto the ePDCCH RBs the device may monitor in a given subframe such thatthe device may receive both, for example, in a window of RBs such as aconsecutive window of RBs without exceeding its supported bandwidth.

The possible location (e.g., in frequency) of the PDSCH indicated by theePDCCH may be based on a certain a priori known or a configuredrelationship such as a relationship described hereinbetween the locationof the ePDCCH RB(s) which the device may monitor and/or attempt todecode and the location of PDSCH RB(s) indicated by that or those ePDCCHRB(s). According to an example embodiment, an eNB may transmit ePDCCHand PDSCH intended for at least a certain or particular device such as areduced BW UE or device in accordance with such a relationship. Thedevice may further monitor and/or attempt to decode ePDCCH and/orattempt to decode PDSCH in accordance with such a relationship.

For example, the frequency span from the lowest (e.g. lowest infrequency) ePDCCH RB to be monitored by the device to the highest (e.g.in frequency in frequency) PDSCH RB to be read by the device may notexceed the BW supported by the device and the frequency span from thehighest (e.g. highest in frequency) ePDCCH RB to be monitored by thedevice to the lowest (e.g. lowest in frequency) PDSCH RB to be read bythe device may not exceed the BW supported by the device.

In an embodiment when the BW supported by the device may be in a windowor group of consecutive RBs, the UE may be provided with and/or may knowin advance whether the PDSCH RBs that may be intended for it may beabove (e.g. in frequency) or below (e.g. in frequency) the ePDCCH RBs itmay monitor.

In such an embodiment, among others, one or more of the followingmethods may be provided, used, and/or applied. For example, according toone embodiment, the PDSCH RBs may be on one side of the ePDCCH RBs suchthat the device may assume that the PDSCH RBs may be (e.g. or maytypically be or may always be) higher or lower in frequency than theePDCCH RBs it may monitor.

In another embodiment, the PDSCH RBs may be divided, for exampleequally, such that a certain or particular number such as half of thePDSCH RBs may be above (e.g. directly above) the ePDCCH RBs and the restmay be below (e.g. directly below) the ePDCCH RBs. For example, thedevice may assume that the PDSCH RBs may be distributed on either sideof the ePDCCH RBs it monitors. In such an embodiment, if the device maymonitor N consecutive ePDCCH RBs or certain RBs in a group of Nconsecutive ePDCCH RBs and the device may support a BW of M RBs, thePDSCH that may be indicated by the ePDCCH may be located in one or moreRBs where these RBs may be located in a set of RBs that includes no morethan (M−N)/2 PDSCH RBs above (e.g. directly above) the N ePDCCH RBs andno more than (M−N)/2 PDSCH RBs below (e.g. directly below) the N ePDCCHRBs. If M−N may be an odd number, the PDSCH that may be indicated by theePDCCH may be located in one or more RBs where these RBs may be locatedin a set of RBs that includes no more than FLOOR[(M−N)/2] PDSCH RBs onone side of the ePDCCH RBs and no more than FLOOR[(M−N)/2]+1 PDSCH RBson the other side of the ePDCCH RBs. Which side may have more PDSCH RBsmay be understood or configured. As an alternative (e.g. where M−N maybe odd), the PDSCH RBs that may be intended for the device may be in aset of RBs that may be no more than FLOOR[(M−N)/2] RBs on each side ofthe ePDCCH RBs. As a numerical example, if the device may monitor 4ePDCCH RBs or one or more RBs in a group of 4 ePDCCH RBs and it maysupport a BW of 6RBs, the device may understand that there may be up toone PDSCH RB for it to read on each side of the 4 ePDCCH RBs. As anothernumerical example, if the device may monitor 4 ePDCCH RBs or one or moreRBs in a group of 4 ePDCCH RBs, and it may support a BW of 15RBs, thedevice may understand that there may be one or more RBs in a set of 5PDSCH RBs for it to read on one side of the 4 ePDCCH RBs and/or one ormore RBs in a set of 6 PDSCH RBs for it to read on the other side of the4 ePDCCH RBs. Such an embodiment may enable a device supporting M RBs toknow which M RBs to receive before decoding the ePDCCH.

In another example embodiment, the PDSCH and ePDCCH RBs may be in aspecific window of X RBs which may be defined or configured where X maybe less than or equal to M where M may be the BW supported by the devicein RBs. For example, in a window of X RBs, the device may monitor ePDCCHRBs that may include ePDCCH RBs that may be configured in the celland/or certain ePDCCH RBs such as ePDCCH RBs that may be designated forthe device or for specific devices such as reduced BW devices that maybe within that window and may assume that RBs in that window that maynot include ePDCCH RBs may include PDSCH RBs that may be intended forthe device.

In another example embodiment, the device may be provided withconfiguration information, for example, by the eNB, which may be viasignaling such as broadcast or dedicated signaling to one or a group ofdevices such as reduced BW UEs or devices regarding the relationshipbetween the location of the ePDCCH RBs and the PDSCH RBs they mayindicate. Such information may include one or more of the following:whether the PDSCH RB(s) may be higher or lower in frequency (e.g.typically higher or lower in frequency) than the ePDCCH RBs to bemonitored by the device; if and/or how the PDSCH RB(s) may be located oneither side of the ePDCCH RBs; a window of less than or equal to M RBsin which the device may find both ePDCCH and PDSCH that may be intendedfor it where M may be the BW supported by the device in RBs; and thelike.

If a device may support a fixed location BW or set of RBs, for example,M RBs, or may be configured with a fixed location BW or set of RBs, forexample, M RBs, which may be changed semi-statically, the device maymonitor (e.g. only monitor) the ePDCCH RBs inside of that BW or those(e.g. M) RBs and may assume that ePDCCH and PDSCH that may be intendedfor it may be in the BW or RBs (e.g. M RBs) it may support or beconfigured with. The device may ignore ePDCCH (e.g., any ePDCCH RBs),which may be outside the BW or set of RBs it may support or beconfigured with. The RBs which may be supported by the device or forwhich the device may be configured with may be, for example, the centeror another M RBs such as the center or another 6, 12, or 15 RBs.

In another embodiment, a device such as a reduced BW UE or device maymonitor ePDCCH in certain subframes and may decode PDSCH in certain(e.g., certain other) subframes and the ePDCCH subframes and PDSCHsubframes for a given device or group of devices may be mutuallyexclusive. The ePDCCH that may be received by a device such as a reducedBW UE or device in subframe n may correspond to PDSCH to be received insubframe n+x such as subframe n+1 or the next subframe in which PDSCHmay be received or another known relationship.

It may be contemplated that the M-PDCCH may be replaced by an ePDCCH inany of the embodiments described herein such as the embodimentsdescribed for M-PDCCH and M-PDSCH in different subframes. The M-PDSCH inthe embodiments described herein may also be replaced by PDSCH which maybe intended for reception by certain devices such as reduced BW UEs ordevices.

In another embodiment, the BW that a reduced BW device may support maycorrespond to a limited number of RBs, for example, 6, 12, or 15, wherethose RBs may not be consecutive. For example, if a device supports MRBs, in a given subframe, the device may and/or may be able to monitorand/or attempt to decode a certain number (e.g. X) of ePDCCH RBs whichmay indicate the location of a certain number (e.g. Y) of PDSCH RBs(e.g. where X+Y<=M).

According to an example embodiment, the X ePDCCH RBs and the Y PDSCH RBsmay not be or may not need to be located in a consecutive window (orgroup) of less than or equal to M RBs. In such an embodiment, the devicemay know in advance (e.g. by at least one of a definition,configuration, relationship, rule, function of a device or cell ID,other parameters, and the like that may be in accordance with one ormore of the solutions described herein), one or more of the location ofa window of consecutive RBs in which the X ePDCCH RBs may be located andthe location of a window of consecutive RBs in which the Y PDSCH RBs maybe located. The sum of the number of RBs in those windows may be lessthan or equal to M. Such an embodiment may enable the device to bufferthe PDSCH RBs while attempting to decode the ePDCCH RBs. This may alsobe extended to include multiple ePDCCH windows and/or multiple PDSCHwindows, for example, provided one or more of the following may apply:the sum of the RBs in those windows may be less than or equal to Mand/or the device may know, for example, in advance, where those windowsmay be (e.g. by at least one of a definition, configuration,relationship, rule, function of a device or cell ID, other parameters,and the like that may be in accordance with one or more of the solutionsdescribed herein).

Channel priority may also be provided and/or used as described herein.For example, a PDSCH may carry ordinary DL SCH data or it may carryspecial data such as broadcast, paging, or a random access response. ThePDCCH or ePDCCH associated with these types of data may be scrambledwith a Cell Radio Network Temporary ID (C-RNTI), system information-RNTI(SI-RNTI), paging-RNTI (P-RNTI), random access-RNTI (RA-RNTI), and thelike respectively. A device such as a reduced BW UE or device may assumeit may have a certain number of (e.g., one) types of DL data to processin a given subframe. For example, paging may have highest priority suchthat if in a given subframe, the device may decode a PDCCH or ePDCCHscrambled with P-RNTI (or another RNTI designated for paging), thedevice may assume there may be no ordinary DL data or system informationblocks (SIBs) for it to process in that subframe, or it may assume thatit may not be required to process such data if it may be present.

In another example, broadcast SIBs may have the highest priority and/orordinary DL data may have the lowest priority. In this example,broadcast data or special data types may have higher priority thanordinary DL data. If in a given subframe, the device may decode a ePDCCHor PDCCH scrambled with the SI-RNTI (or another RNTI designated forbroadcast data) or the RNTI for another special data type, the devicemay assume there may be no ordinary DL data for it to process in thatsubframe or it may assume that it may not be required to process suchdata if it may be present.

As described herein, in embodiments, DCI formats may be provided and/orused (e.g. with a device such as a reduced BW UE or MTC device). Forexample, a compact DCI may be defined for devices such as UEs or MTCdevices such that downlink control channel coverage may be increasedwhile supporting the functionalities for such devices. Additionally, aDCI associated with PDSCH may include at least one of following:two-step or two-type resource allocation (RA) information; a modulationand coding scheme (MCS); a hybrid automatic repeat request (HARQ)process number; a new data indicator (NDI); a redundancy version (RV);and the like.

In the two-step resource allocation (RA) information, two types of RAinformation may be included in a DCI such as MTC band indication andresource block indication for the device. As part of a first type of RAinformation, a device band index such as a UE or MTC device band indexmay indicate which subband may be used for the device. In thisembodiment, the subband size may be the same as a RBG (Resource BlockGroup) size P for the system bandwidth (N_(RB) ^(DL)). If N_(RB)^(DL)=25, and the RBG size may be 2 as shown in the table of FIG. 30. Ifone RBg may be used for a group of devices, the band index may use ┐log₂N_(RGB)┌ bits where N_(RBG)=┐N_(RB) ^(DL)/P┌.

As part of a second type of RA information, a RB index for PDSCHtransmission may be indicated. The RB index may be indicated by bitmapwhere the RBG size P′ may be related to the reduced bandwidth. As such,6 bits may be used if 6RBs may be defined as reduced bandwidth for thedevice, which may be shown in the table of FIG. 30B.

In example embodiments, the first and second type of RA information maynot be transmitted in the same DCI. Additionally, the two types of RAinformation may be informed to a device in at least one of followingmanners.

In one example embodiment, the first type of RA information may beinformed to a device via a common DCI which may be shared with multipledevices while the second type of RA information may be informed via aDCI associated with a PDSCH. In another example embodiment, the firsttype of RA information may be informed to a device via a broadcastingchannel (e.g. SIB-x) and the second type of RA information may beinformed via a DCI associated with a PDSCH. According to anotherexample, the first type of RA information may be configured via higherlayer signaling and the second type of RA information may be informedvia a DCI associated with a PDSCH. Additionally, the first type of RAinformation may be implicitly detected from a scrambling sequence forthe reference signal in the PRB candidates and the second type of RAinformation may be informed via a DCI associated with a PDSCH.

According to an embodiment, a modulation coding scheme (MCS) may also beprovided and/or used. For example, a MCS set may be reduced from 5 bitsto 4 or 3 bits. If a single DCI may be applicable for a device for PDSCHtransmission, the reduced MCS set may be used and a new DCI format maybe defined such as DCI format 2D. The reduced MCS set may be used forfall-back transmission mode. For example, if DCI format 1A and DCIformat 2D may be used for a device, the DCI format 1A may have 3 or 4bit MCS set and the DCI format 2D may have 5 bit MCS set. A newmodulation order may be introduced such as a Binary Phase Shift Keying(BPSK) modulation order. BPSK may be introduced such that that the MCStable for the device may support {BPSK, quadrature PSK (QPSK), 16quadrature amplitude modulation (QAM), and 64QAM}. In an embodiment,BPSK may replace the 64QAM modulation order and the TBS size may bereduced accordingly.

A HARQ process number and/or channel state information feedback mayfurther be provided and/or used as described herein. For example, in anembodiment, the number of bits for HARQ process number may be changedaccording to the subframe configuration in multi-type subframeconfiguration.

Additionally, for CSI feedback, various alternatives as described belowfor reduced bandwidth configuration for low cost device may beconsidered according to the bandwidth reductions in RF, baseband,control region, and/or data region.

For example, the CSI reporting modes for reduced BW MTC may be itcategorized as set forth below. In a first category, if there may bereduced bandwidth for both RF and baseband and the device may be limitedto receive certain sub-bandwidths of the entire system bandwidth thenone or more of the following may be provided, used, and/or applied. If areduced BW for a device may be equal to the minimum BW in a network orsystem such as a LTE systems (e.g. the reduced BW=6 RBs), there may beno subband CSI reporting such as CSI reporting mode 1 and mode 1a may beused for the device, which may be shown in the table of FIG. 31. Thereduced BW device may use partial or truncated cell-specific referencesignals (CRS) and/or CSI-RS for a rank indicator (RI), channel qualityindicator (CQI) and precoding matrix indicator (PMI) measurement.Additionally (e.g. for release 8/9/10,) a subband location index L forperiodic CQI reporting may be defined as

${L = \left\lceil {\log_{2}\left\lceil \frac{N_{RB}^{DL}}{kJ} \right\rceil} \right\rceil},$

where k may be the number of RBs per subband and J may be the bandwidthparts (BP).

For example, if NRB=110 (RBs), k=8, and J=4, L=2 bits (e.g. 4 subbandlocations) for signaling the subband location for subband reporting maybe provided and/or used. In the device, the N_(RB) ^(DL) may be replacedfor the reduced BW as follows

${L = \left\lceil {\log_{2}\left\lceil \frac{N_{RB}^{DL\_ MTC}}{kJ} \right\rceil} \right\rceil},$

where N_(RB) ^(DL) ^(_) ^(MTC) may be the BW of MTC that may besupported.

In a second category, if a reduced bandwidth may be for baseband forboth data channel and control channels and there may be no BW reductionfor RF, one or more of the following may be provided, used, and/orapplied. If a reduced BW for MTC may be equal to the minimum BW in anetwork or system such as LTE systems, there may be no subband CSIreporting used for the device. The starting RB location or index forwideband and subband CSI reporting may be signaled by the base stationwhere the signaling may be via a RRC or DL control channel. A reduced BWdevice may use partial or truncated CRS and/or CSI-RS for a RI, CQI andPMI measurement. The subband location index L, the N_(RB) ^(DL) may bechanged to the reduced BW of the device as follows

${L = \left\lceil {\log_{2}\left\lceil \frac{N_{RB}^{DL\_ MTC}}{kJ} \right\rceil} \right\rceil},$

where N_(RB) ^(DL) ^(_) ^(MTC) may be the BW of devices that may besupported for data and control channels.

In a third category, if a reduced bandwidth may be for data channel inbaseband, while the DL control channels may still be allowed to use thecarrier bandwidth and there may be no BW reduction for RF, the followingmay be used, provided, and/or applied. If a reduced BW for a device maybe equal to the minimum BW in a network or system such as LTE systems,there may be no subband CSI reporting used for the devices. The CSImeasurement method may be reused from rules such as LTE Release 10 rulesor to reduce CSI complexity for the device. Additionally, the startingRB location or index and the number RBs for wideband and subband CSIreporting may be signaled by the base station. The subband locationindex L for periodic CQI reporting may be reused (e.g. from LTE Release10) and defined as follows

$L = \left\lceil {\log_{2}\left\lceil \frac{N_{RB}^{DL}}{kJ} \right\rceil} \right\rceil$

or the N_(RB) ^(DL) may be changed to the reduced BW of the device asfollows

${L = \left\lceil {\log_{2}\left\lceil \frac{N_{RB}^{DL\_ MTC}}{kJ} \right\rceil} \right\rceil},$

where N_(RB) ^(DL) ^(_) ^(MTC) may be the BW of the device that may besupported for data channel.

A device such as a UE or MTC device may be configured to report CSI withat least one of following behaviors. In a first behavior, a CSIreporting type may include and/or use at least one of following: asubband and/or wideband CQI; a subband and/or wideband PMI; a widebandRI; a best subband index (BSI); and the like. In the later embodiment,more than one subband may be defined within a system bandwidth N_(RB)^(DL) and a subband index (e.g. a preferred subband index) may beselected at a device receiver such as a UE or MTC receiver. In addition,the subbands may be defined within a reduced bandwidth that may be usedas a candidate for device resource allocation such as MTC resourceallocation.

In a second behavior, a device may report CSI for a system bandwidth(N_(RB) ^(DL)) and a reduced device bandwidth (N_(RB) ^(DL) ^(_)^(MTC)). If N_(RB) ^(DL)≥N_(RB) ^(DL) ^(_) ^(MTC), a BSI may be reportedfor N_(RB) ^(DL) and CQI/PMI and/or RI may be reported for N_(RB) ^(DL)^(_) ^(MTC). If N_(RB) ^(DL)=N_(RB) ^(DL) ^(_) ^(MTC), the BSI may notbe reported and CQI/PMI and/or RI may be reported for N_(RB) ^(DL).

In a third behavior, a device such as a UE or MTC device may support oneof PUCCH and PUSCH reporting. For example, PUCCH reporting modes may besupportable for such a device in an embodiment.

According to an example embodiment, a device such as a UE or MTC devicemay be defined as a new UE category that may supports low data rateand/or a reduced bandwidth. In such an embodiment, a UE categoryspecific CSI reporting mode may be defined. For example, a UE category 0may be defined and the supportable soft buffer size, multi-layertransmission, and CA capability may be defined lower than other UEcategories. Additionally, multi-layer and carrier aggregation may not besupported for the UE category 0 and the soft buffer size may be smallerthan UE category 1 as shown in the table of FIG. 32.

In another embodiment, the maximum number of DL-SCH transport block bitsand the maximum number of bits of a DL-SCH transport block in the tableof FIG. 32 may be defined with n-transmission time interval (TTI) for anew UE category where the n may be equal to or larger than 2 and may bedefined at least one of following: n may be a predefined number; n maybe defined according to at least one of system parameters such as systembandwidth, duplex mode (e.g., FDD or TDD), and/or physical cell ID; nmay be configured via broadcasting, multicasting, or dedicatedsignaling; and the like.

Data channels with a reduced peak rate may be provided and/or used asdescribed herein. For example, multi-frame or multi-subframe TDMA tomultiplex data and control transmission may be used. To provide suchmulti-frame or multi-subframe TDMA, systems and/or methods that maydefine a multi-type subframe and/or radio frame to enable or allow adevice such as a UE or MTC device to work in the smaller bandwidthwithin a wider bandwidth supporting a legacy device such as a LTE UEwith a similar coverage.

Additionally, a multi-type subframe definition may be provided and/orused. For example, a device may receive downlink control channels anddata channels in a different subset of subframes and/or radio frames.The downlink control channel region (e.g. the M-PDCCH region) for thedevice and the downlink data channel region (e.g. the M-PDSCH region)may be defined using one or more of following techniques. In oneembodiment, a fixed structure in a radio frame may be used where theM-PDCCH region and M-PDSCH region may be interlaced in a radio frame andthe M-PDCCH region and M-PDSCH region may be defined with consecutivesubframes as shown in FIG. 3.

In another embodiment, a configurable structure or configurations with apredefined set may be used where multiple configurations of a M-PDCCHregion and M-PDSCH region may be defined such that the ratio betweencontrol channel overhead and downlink resource utilization may behandled by an eNB according to the cell environment. The table of FIG.34 shows an example embodiment for the predefined set based M-PDCCHregion that may be defined as ‘C’ in the table and the M-PDSCH regionconfiguration that may be defined as ‘D’ in the table.

Additionally, a flexible configuration such as a full flexibleconfiguration with a bitmap via higher layer signaling may be used wherea bitmap may be transmitted from higher-layer signaling that mayindicate the M-PDCCH region and M-PDSCH region configuration. If theconfiguration may be defined with a radio frame, the bitmap size may be10-bits.

In an example embodiment, from a device perspective such as a UE or MTCdevice perspective, the configuration of M-PDCCH region and M-PDSCHregion may be further restricted to a subset of M-PDCCH and M-PDSCHsubframes in a device-specific manner. For such a method, a device suchas a UE or MTC device may receive configuration information from one ormore of the following: a preconfigured set, a fully configurable set,and the like. In a predefined configuration set, the multiple ofconfigurations may be pre-defined and the configuration number may beprovided or informed to devices in a device-specific manner as shown inthe table of FIG. 35 where ‘N’ may denote a null subframe in which adevice may fall into micro-sleep mode, in which a UE may not receive anysignal or perform measurement only. Additionally, in a fullyconfigurable set, a bitmap is transmitted for each region and thesubframe not used for either M-PDCCH region or M-PDSCH region may beconsidered as a null subframe.

A multi-type subframe operation may also be provided and/or used asdescribed herein. For example, in an embodiment, for M-PDCCH receptionand its associated M-PDSCH reception, behaviors of a device such as a UEor MTC device may be defined according to or using one or more offollowing methods or procedures.

For example, in one embodiment, a device may assume that the PDCCHtransmission for downlink grant may be within a subframe subset in aradio frame. The subframe numbers in the subset in a radio frame for aPDCCH transmission may be 10, 4, 5, 91. The device may assume that onesubframe out of a subframes subset may include a PDCCH for the device.The PDCCH transmission for a downlink grant may be confined to {4, 9}.The PDCCH transmission for an uplink grant may be confined to {0, 5}.The search space may be further confined to a UE- or device-specificmanner such that a device A may be restricted to see the subframe {4}for a downlink grant reception while a device B may be restricted tosearch the subframe {9} for a downlink grant reception.

Additionally, according to an embodiment, a device such as a UE or MTCdevice may assume that a downlink control channel may be located acrossthe two consecutive subframes {9, 0} and {4, 5}. A PCFICH may betransmitted with the same CFI value in the consecutive subframes {9(e.g. in previous subframe), 0} and {4, 5} to support a bundled M-PCFICHas described above. A PDCCH may be transmitted in one subframe of {9, 0}and {4, 5}

In another embodiment, a device such as a UE or MTC device may receivethe PDSCH in the subframe n if a corresponding PDCCH may be received inthe subframe n-j where j may be defined according to one or more offollowing: j may be pre-defined number such as j=2; j may be indicatedin the corresponding PDCCH in each DL grant; j may be configured byUE-specific RRC signaling; and the like.

A device such as a UE or MTC device may transmit the PUSCH in thesubframe n if corresponding PDCCH may be received in the subframe n-k,where k may be defined according to one or more of following: k may be apre-defined number such as k=2; k may be indicated in the correspondingPDCCH in each DL grant; k may be configured by UE-specific RRCsignaling; and the like.

Additionally, TTI bundling for a PDCCH and PDSCH transmission may beprovided, used, and/or assumed. For example, a device such as a UE orMTC device may receive a PDCCH across subframes {4, 5} and thecorresponding PDSCH across the subframe {6, 7, 8}. The HARQ process mayalso be bundled within {6, 7, 8}. The same behavior may be defined forthe sets of subframe {9 (e.g. in the previous subframe), 0} and {1, 2,3}.

In an embodiment, a device such as a UE or MTC device may provide, use,and/or assume that a subset of a radio frame may not include informationfor the device such that a radio frame based sleep mode may be used toreduce to computational power at the MTC device receiver.

A transport block size (TBS) may also be used and/or provided asdescribed herein. In an embodiment (e.g. a first method), a TBS tablemay be defined for devices such as a UE category 0 device as shown inthe table of FIG. 36. In such an embodiment, the subset of TBS table forUE category 1 may be used as the UE category 0 may supports up to 6PRBs. However, the maximum supportable number of PRBs may not berestricted to 6 PRBs and an additional number of PRBs may be also used.The table of FIG. 36 also shows the TBS available for a UE category 0and its associated MCS index and modulation order.

According to another embodiment (e.g. a second method), the TBS tablefor UE category 0 may be defined with smaller TBS size according to thenumber of PRBs to increase the downlink coverage and the TBS table mayhave at least one of the following properties. For a first property, ina given MCS index, a single TBS size may be used irrespective of thenumber of PRBs that may be assigned for the device if an eNB mayconfigure the fixed TBS size. In this embodiment, the TBS size may bethe same as that of N_(PRB)=1. The TBS size may be configured by higherlayer signaling. For a second property, at least a portion of the MCSindex for the highest modulation order may be reused with a lowestmodulation order and its associated TBS size to support a smaller TBSsize in a given number of PRBs. For a third property, an eNB mayoverride the maximum TBS size with N_(TBS) ^(restrict) and a TBS largerthan N_(TBS) ^(restrict) may be replaced with a predefined number. Forexample, a TBS size for N_(PRB)=c may be used where c may be apredefined number. For a fourth property, a subset of the MCS may have afixed TBS regardless of the number of PRBs. The table of FIG. 37 showsan example of a TBS table using the properties in the above embodiment(e.g. the second method).

According to example embodiments, broadcast and/or multicast channelsmay be provided and/or used. For example, network techniques may be used(e.g. to schedule DL system information and paging messages, and thelike) for low-cost devices such as UEs or MTC devices that may support areduced bandwidth.

To provide such techniques and/or broadcast or multicast channels, anindication such as a MIB indication of narrower bandwidth device supportmay be provided and/or used. For example, a E-UTRAN or the eNB mayindicate cell support to the narrower bandwidth devices including UEsand low cost MTC devices in the master information block (MIB) broadcastsince the MIB may be transmitted in the center frequency of the cell.The indication may take some of the current sparing bits. Additionally,the indication may include one or more of the following: general supportfor narrower bandwidth reception and/or transmission; a narrowestbandwidth UE support category (e.g. 1.4 MHz or 3 MHz or 5 MHz); anarrower bandwidth receive signaling support category (e.g. newM-PCFICH, M-PDCCH, M-PHICH in the legacy “control region” or in thelegacy “data region”) and possible physical resource used (e.g. thenumber of symbols and number of PRBs and frequency location); a newcommon control region space support (e.g. in a current “control” regionor in “data” region) for narrower bandwidth receiver; and the like.

In such techniques and/or broadcast or multicast channels, a commonsearch space for a narrower bandwidth device may be provided and/orused. For example, in some embodiments, a special common search spacewhere the narrower bandwidth device such as a UE or MTC device may findthe SI-RNTI, P-RNTI and RA-RNTI may be defined for the narrowerbandwidth device to receive the vital system signals. In one embodiment,this may be defined in the data region. The new common search space fornarrower bandwidth device reception may be located in the symbol-k (e.g.where k=CFI, 0 based), symbol k+1, to symbol k+n, where n may beconfigured or predefined with the frequency range f. The new commonsearch space that may be spread over the frequency range f (e.g. wheref=frequency bandwidth that may be supported for the device which may besmaller than system bandwidth for legacy devices such as LTE UEs).

Alternatively, this may be defined in the control region. In theexisting control region center frequency portion where the narrowerbandwidth device may receive data or information, the device may claim aUE specific search space as the “new common search space for narrowerbandwidth UE device” by not allocating C-RNTIs or temporary-C-RNTIs thatmay result a UE specific search space located into those claimed spaceto the devices or UEs in this serving cell.

Additionally, in such techniques and/or broadcast or multicast channels,a narrower bandwidth device indication may be provided to the network.For example, a device such as a UE or MTC device may indicate itself asa “special” device such that that the base station, E-UTRAN, eNB, andthe like associated with the network may be able to transmit controlsignals and data in the channels such as a random access response (e.g.with RA-RNTI) that may be suitable for the reception by the narrowerbandwidth devices or UEs.

As such, in an example embodiment, an indication may be provided to theeNB. The device may provide such an indication during a random accessprocedure such as during an initial connection procedure. For example,in a PRACH transmission (e.g. as shown in FIG. 12), a contention-basedprocedure may be performed where the device may choose a preamblesequence and a time (subframe)-frequency resource.

The following embodiments or methods may be proposed to enable an eNB todistinguish a regular UE from a narrower bandwidth device based on therandom access (PRACH) resources the device may use. For example, in oneembodiment, a device may use (e.g. choose from) certain random accessresources such as preamble sequences and/or time and/or frequencyresources that may be designated for use or otherwise known to be usableby at least narrower bandwidth devices, MTC device, or a specific UEcategory. Such resources may be reserved for such devices, may be usableby other devices, and/or may be a new set of resources or a subset ofexisting resources.

In another embodiment or method, the device may transmit an additionalbit with the preamble transmission (e.g. for RACH message 1 via PRACH,to indicate its device type such as a narrower BW device, the currentRACH message 1 may carry 6 bits information with 5 bits for a preambleID, 1 bit for RACH message, and 3 length indications). This extra bitmay be used by the eNB to distinguish PRACH preamble reception fromeither a regular device or narrower bandwidth device.

According to yet another example embodiment or method, the device maytransmit a small payload following (e.g. immediately following), thepreamble to convey additional information such as a device type, a UEidentity, a scheduling request, other small amounts of data, and thelike. This may be a single transmission composed of RACH preamble andRACH message where the RACH message may convey additional information asdescribed above. The preamble may be used as reference for thedemodulation of the RACH message (e.g. payload) part, and, thus, the ULdemodulation reference signals may be saved (e.g. may not be needed).Once the eNB may successfully detect the PRACH preamble, it may furtherproceed to decode the RACH message part. FIG. 38 illustrates an exampleembodiment of the transmission of a PRACH with a payload.

In another example, the UE may transmit a small payload (e.g. a RACHpayload) in resources associated with the preamble resources such thatbased on the preamble and/or time and/or frequency of the preamble theresources including time and/or frequency resources to use for thepayload may be known to the device and the eNB. Once the eNB maysuccessfully detect the PRACH preamble, it may further proceed to decodethe RACH message part.

When the eNB or network component may detect the special preamble (e.g.a modified preamble or preamble plus payload) and/or a particular orcertain random access resource such as a certainpreamble/subframe/frequency combination that may be selected from acertain set of random access resources from the device, the eNB ornetwork component may be able to determine that the incoming message orrequest may be from a narrower bandwidth device. If the eNB or networkcomponent may determine that the incoming random access message orrequest may be from a narrower bandwidth device, the eNB or networkcomponent may following a special set of rules, for example, forsignaling and/or data transmission to and/or from this device (e.g. aneNB or network component may keep certain signaling and/or datatransmission for this UE within the narrower device receive range and/orinto specially defined channels and spaces).

FIG. 39 provides an example of a modified contention-based RA procedureto handle narrower bandwidth device indication. As shown in FIG. 1, thedevice such as the UE may provide a PRACH preamble to the eNB, E-UTRAN,and/or network component at 1. As described above, the eNB or networkcomponent may determine whether the device may be a narrower bandwidthdevice at 1A. If the eNB or network component may determine that thedevice may not be a narrower bandwidth device, a regularcontention-based procedure or method such as the procedure shown in FIG.12 may be performed at 1B. If the eNB or network component may determinethat the device may be a narrower bandwidth device, a contention-basedprocedure or method for a narrower bandwidth device (e.g. a specialprocedure or method) may be performed. In such a procedure, at 3, arandom access response for a special device or a narrower bandwidthdevice may be provided from the eNB or network component. Then, at 4, ascheduled transmission for a special device or a narrower bandwidthdevice may be provided from the device or UE to the eNB or networkcomponent and, at 5, a contention resolution for a special device or anarrower bandwidth device may be provided from the eNB to the device orUE. The details of aforementioned methods may be described in moredetail below.

For example, certain or particular random access resources may be usedby narrower bandwidth devices. For example, in one embodiment, thenetwork may reserve a special set of RACH preambles (e.g.random-access-preamble-group-c) for the use of the narrower bandwidthdevices and the narrower bandwidth device may select one of them forrandom access (e.g. an initial random access). For preamblepartitioning, existing RACH preambles may be partitioned and a subset ofRACH preambles may be used for a device such as a UE or a MTC devicesuch that an eNB or network component may differentiate a narrowerbandwidth device before transmitting RA response. Alternatively, acombination of preamble partitioning and additional PRACH resources maybe used. Additional RACH preambles may further be provided andpartitioned such that some of such preambles may be used for a narrowerbandwidth device.

In another example embodiment, the network may provide a set ofpreambles and/or subframes and/or frequencies that may be used by anarrower band device random access. This set of random access resourcesmay be a subset of the cell's or eNB's existing random access resources(e.g. those usable by R8/9/10 UEs) or may be a separate set of randomaccess resources. A subset or unique identification may be provided viaRRC signaling such as broadcast or handover (e.g. mobility) signaling ormay be a fixed identification (e.g. by specification). Additional randomaccess (PRACH) resources may be allocated in a different time and/orfrequency location. As similar with TDD, an additional PRACH resource ormultiple PRACH resources may be defined in FDD. The additional ormultiple random access (e.g. PRACH) resources or a subset thereof may beused by either a device such as a UE or MTC device that may support anarrower bandwidth or by other UEs (e.g. a MTC/Rel-11 regular UE).Whether a device may use these resources may depend on whether thedevice may recognize that these resources exist (e.g. whether the devicemay read the related broadcast information) or whether the device maydecode ePDCCH. For a subset of the random access resources, there may beno limitation on which devices may use these resources. In an exampleembodiment, such a set of random access resources may be or may includethe random access resources configured in the cell or eNB.

Based on the random access (PRACH) resources including the set ofresources, the subframe or frequency of the resources, or the preamblethat may be used by the device, the eNB may respond differently such asby providing the random access response (e.g., msg2 and/or others), DLcontrol information in a PDCCH or ePDCCH, or both. For example, if twosets of PRACH resources may be defined (e.g. a RACH group 1, RACH group2) and a device may transmit a RACH preamble in RACH group 1, the devicemay expect to receive a RA response (e.g., msg2) via a legacy PDCCH.Otherwise, if the device may transmit a RACH preamble in group 2, thedevice may expect to receive a RA response via ePDCCH. In thisembodiment, a RACH group 1 may be backward compatible (e.g. usable byR8/9/10 UEs).

As another example, if two sets of PRACH resources may be defined (e.g.RACH group 1, RACH group 2) and a device may transmit a RACH preamble inRACH group 1, a device may expect to receive a RA response (e.g. msg2)via a legacy PDCCH. Otherwise, if the device may transmit a RACHpreamble in group 2, a RA response may be provided via PDCCH and ePDCCHand a device may use either (e.g. based on its capabilities) to obtainthe RA response. In this example, both RACH groups may be backwardcompatible (e.g. usable by R8/9/10 UEs).

As another example, the eNB may respond differently based on thefrequency of the random access resources that may be used by the devicesuch as by responding via ePDCCH or both PDCCH and ePDCCH when thefrequency may be within the BW of reduced BW devices.

When the device may receive certain random access response messages(e.g. msg2 for a contention based procedure) via ePDCCH, the device mayexpect that the corresponding PDSCH may be located in the narrowerbandwidth, for example, to ensure the narrower BW devices may access theresponse.

According to example embodiments, based on the random access (PRACH)resources including the set of resources, the subframe or frequency ofthe resources, or the preamble that may be used by the device, the eNBmay respond differently such as by providing the DL control informationfor the random access response (e.g. msg2 and/or others) and/or thePDSCH random access response (e.g. msg2 and/or others) in a manner inwhich such a response or responses may be received and decoded by atleast certain devices such as reduced BW UEs or devices (e.g. MTCdevices).

For example, based on the random access (PRACH) resources that may beused by the device, the eNB may provide the DL control information forthe random access response in ePDCCH RBs that may be within the BW or aset of RBs within the BW that the device such as the reduced BW UEs ordevices may decode. This may, for example, include the center M RBs,where M may be the BW that may be supported by reduced BW UEs/devices.It may include the center X RBs, X<=M, where M may be the BW that may besupported by reduced BW UEs/devices and where X may be known or the UEmay be informed of the value of X via signaling such as RRC signalingwhich may be broadcast or dedicated signaling. It may include a definedor configured set of X RBs, X<=M where M may be the BW that may besupported by reduced BW UEs or devices.

In embodiments, the device may be informed of the configuration by theeNB via signaling such as RRC or dedicated signaling which may bebroadcast. The configuration may also be specific to at least one of therandom access response according to one embodiment. For example, basedon the random access (PRACH) resources that used by the device, the eNBmay provide the random access response in RBs such as PDSCH RBs.

Additionally, a reduced BW device such as a UE or MTC device may decodeat least one of the following: the center M RBs where M may be the BWthat may be supported by reduced BW devices; the center X RBs, X<=Mwhere M may be the BW that may be supported by reduced BW UEs/devices;and/or X, which may be known by the device or may be provided to thevalue of X via signaling such as RRC or dedicated signaling that may bebroadcast.

As such, a defined or configured set of X RBs, X<=M, where M may be theBW that may be supported by reduced BW device may be used. The devicemay be informed of the configuration by the eNB via signaling such asRRC signaling which may be broadcast or dedicated signaling. Theconfiguration may be specific to at least one random access response.

In another example, the above examples may be combined such that the eNBmay respond by providing both the ePDCCH RBs and the PDSCH RBs for therandom access response within the BW or may provide a set of RBs thatthe devices such as reduced BW UEs or devices may decode. For example,if the device may be expected, defined, and/or configured to decode aset of up to X RBs, both the ePDCCH RBs and the PDSCH RBs may be locatedby the eNB within that set of X RBs, which may be a set of X consecutiveRBs.

Based on the random access (PRACH) resources including the set ofresources, the subframe or frequency of the resources, or the preamblethat may be used by the device, the eNB may respond differently whenallocating UL resources to the device such as for the device response ordata transmission. For example, if the device may use certain randomaccess resources (e.g. a RACH preamble of group 2 when there are 2groups of resources), the device may expect that a UL grant it mayreceive may be for resources in the narrower bandwidth. Otherwise, thedevice may expect that a UL grant may allocate resources in the full BWof the cell.

Additionally, in an embodiment, a flexible duplexer may be used by adevice such as a narrower BW device or UE. In such an embodiment, thedevice may be able to support uplink transmission outside the narrowerBW centered at the center of the BW of the cell as long as theallocation may not exceed the total BW supported by the device. Forexample, if the device may support a 5 MHz BW, it may shift itstransmission band to a different 5 MHz of a larger, for example, 20 MHzband as long as there may be enough time for the switch.

A device such as a reduced BW UE or device may choose a random access(PRACH) resource that may be defined by a preamble, one or morefrequencies and subframes, and the like from the defined or configuredset or subset of such resources that may indicate to the eNB that it maybe a reduced BW device. The device may also exclude other PRACHresources from its selection procedure.

Additionally, a reduced device may monitor and/or attempt to decodePDCCH and/or ePDCCH known or configured to be intended for one or moreDL random access messages, (e.g. the random access response messageand/or contention resolution message) for at least a reduced BWUE/device.

In an embodiment, the device may also inform the eNB or, for example,other network components of reduced BW support during a random accessprocedure. For example, a device may perform one or more of thefollowing. The device may inform the eNB in one of the random accessmessages such as in the device or UE response following the randomaccess response or after contention resolution whether it may supportflexible UL transmission or not (e.g. via a capability message).

The device may also inform the eNB in one of the random access messagessuch as in the device or UE response following the random accessresponse or after contention resolution whether it may be a device asdescribed herein such as a MTC device or narrow BW device. For example,if device or UE resources may be used by narrower BW device, but may nothave been reserved for a narrower BW device, the eNB may respond in thenarrower BW (e.g. by using ePDCCH or by using ePDCCH and/or PDSCH RBs ina BW or a set of RBs the narrower BW the device may support or decode)and may be informed as to whether the device may really be a narrower BWdevice. If the device may not inform the eNB, the eNB may assume the UEmay not be a narrower BW device and may use a wider BW for subsequent ULand/or DL transmission for the device.

According to an example embodiment, the device may use a new cause inthe RRC Connection Request message that may identify the device as areduced BW device. This cause may indicate a mobile originated (MO) callfrom a reduced BW device and/or a mobile originated (MO) call from adevice that may be both reduced BW and delay tolerant. In suchembodiments, a new cause may be added in the RRC Connection Requestmessage for a mobile terminated (MT) call response from a reduced BWdevice which may be used by a device to indicate itself as an MT callanswer from a device that may be reduced BW or both reduced BW and delaytolerant. In embodiments, this may not be used for a mobile terminated(MT) call, since for a MT call, the network may already know that thedevice may be a reduced BW device using the methods or proceduresdescribed herein. According to an example embodiment, the device may usethis cause if the BW supported by the device may be less than the cellBW (e.g. the cell DL BW) that may be provided in the cell broadcastinformation.

In another example embodiment, the device may include additionalinformation in the RRC connection request such as identification of thedevice as a reduced BW device and/or an indication of the BW it maysupport.

Another scheme (e.g. which could be used independently or in conjunctionwith the above cause or indication embodiments) for confirming theidentity such as a reduced BW of a reduced BW device in the stages of amsg3 (e.g. RRC Connection Request) and/or a msg4 (e.g. ContentionResolution) may be to define a special format or value range that may,for example, be used by a reduced BW device, for the “randomValue” IE inthe InitialUE-Identity part of the RRC Connection Request message (e.g.that may be over CCCH). For example, a certain bit pattern for a portionof the randomValue such as “111” for the 3 most significant bits or acertain value range (e.g. 0˜100000 where randomValue may be a 40-bitquantity) may be used for the reduced BW devices.

When the eNB or other network component may receive the device msg3 withthe “randomValue” in the defined pattern or in the defined value range,the reduced BW supporting eNB may consider the device a reduced BWdevice and may then in the Contention Resolution message (e.g. msg4) fora reduced BW UE/device add a certain value offset (e.g. 7) to thedevice's randomValue sent in msg3 as the “UE Contention ResolutionIdentity.” After adding the offset, the eNB may transmit the UEContention Resolution Identity back to the device in msg4. For reducedBW devices that may know the offset rule), if the“randomValue”+offset=the “Contention Resolution Identity,” the devicemay consider the contention resolution successful. Additionally, for thelegacy devices, if they may accidentally put a “randomValue” in msg3 asa reduced BW device and may then receive the Contention Resolution Id(msg4), since legacy UEs may not know the new rule, such devices mayconsider the resolution a failure, because the received “ContentionResolution Id” may not match the initial randomValue sent in msg3 as aresult of the offset. In this embodiment, the legacy UEs may carry onanother round of RRC connection request.

Regardless of the random access resources available, the narrower BWdevice may use resources in the BW it may support. For example, whenperforming the random selection of a PRACH resource from the availablePRACH resources, the UE may include in the selection process theavailable PRACH resources that are within the BW the UE supports (e.g.and may use such resources and not resources outside the BW it maysupport).

According to an example embodiment, an extra 1-information bit that maybe carried in PRACH preamble to indicate narrower bandwidth devices maybe used. For example, it may be useful for the eNB or other networkcomponents to have a way to distinguish which RA preamble may come froma narrow BW device or a regular device such that the eNB may allocate acorresponding RA response for the narrower BW devices.

Adding one information bit to the current PRACH preamble (e.g. by usingBPSK) may be used to differentiate a narrow BW device from a regulardevice (e.g. LTE UEs). In such an embodiment, PRACH preamble sequencesmay not be reserved or portioned to distinguish a regular device ornarrower bandwidth devices. As such, the SIB information may be simpler,because there may be no need to broadcast a special set of reservedpreamble sequences for narrower bandwidth devices. Also, E-UTRAN ornetwork components (e.g. the eNB) may perform PRACH preamble detectionwithout knowing the type of device.

For example, the time-continuous random access signal s(t) defined byfor a regular device may be modified to support a MTC device or othernarrower BW UE or device as follows:

${s(t)} = {\beta_{PRACH}{\sum\limits_{k = 0}^{N_{ZC} - 1}\; {\sum\limits_{n = 0}^{N_{ZC} - 1}\; {{x_{u,v}(n)} \cdot e^{{- j}\frac{2\pi \; {nk}}{N_{ZC}}} \cdot e^{j\; 2{\pi {({k + \phi + {K{({k_{0} + \frac{1}{2}})}}})}}\Delta \; {f_{RA}{({t - T_{CP}})}}} \cdot e^{j\; \theta}}}}}$$\theta = \left\{ \begin{matrix}{0,} & {{regular}\mspace{14mu} {UE}} \\{\pi,} & {{narrower}\mspace{14mu} {BW}\mspace{14mu} {{UE}/{MTC}}\mspace{14mu} {type}}\end{matrix} \right.$

where 0≤t<T_(SEQ)+T_(CP), β_(PRACH) may be an amplitude scaling factorto conform to the transmit power P_(PRACH), and k₀=n_(PRB) ^(RA)N_(sc)^(RB)−N_(RB) ^(UL)N_(sc) ^(RB)/2. The location in the frequency domainmay controlled by the parameter n_(PRB) ^(RA). Additionally, the factorK=Δf/Δf_(RA) may account for the difference in subcarrier spacingbetween the random access preamble and uplink data transmission. Δf=15KHz may also be subcarrier spacing for uplink SC-FDMA. In exampleembodiments, the variable Δf_(RA)=1250 Hz may the subcarrier spacing forthe random access preamble and the variable φ=7 in FDD case. P_(PRACH)may be the PRACH preamble sequences length in FDD case and x_(u,v)(n)may be the u^(th) root Zadoff-Chu sequence.

According to an example embodiment, a device such as a reduced BW UE ordevice may add such a bit to its PRACH preamble transmission.Additionally, when an eNB or cell may receive this bit from a device,the eNB or cell may understand the device to be a reduced BW device andmay act in accordance with that knowledge, for example, by acting inaccordance with one or more of the embodiments described herein.

In an embodiment, a small payload with a PRACH preamble may be providedand/or used as described herein. For example, a narrower BW device maytransmit a small payload with the PRACH preamble. The payload may followthe preamble or may be in resources associated with the preamble and/ora PRACH time and/or frequency resource carrying the preamble. Forexample, the narrower bandwidth device may transmit the narrowerbandwidth device identity and scheduling request information (currentRACH message type 3) together with the PRACH preamble.

A modified contention-based RACH procedure for narrower bandwidth deviceindication based on transmitting a preamble with narrower bandwidthdevice identity may be shown in FIG. 40. As shown in FIG. 40, a devicesuch as a UE may transmit a PRACH preamble that may include the deviceor UE identity (e.g. in a bit or other indication) as well as ascheduling request (SR). In response thereto, the E-UTRAN or othernetwork component (e.g. a eNB) may provide a random access response andcontention resolution at 2 as described herein. Such an embodiment mayapply in various scenarios such as when the device may have a networkassigned device or UE identity (e.g. C-RNTI). Additionally, for acontention based RA procedure for an initial access, the device mayreceive its C-RNTI in the RA response (e.g. msg2), and, as such, thisembodiment may not be applicable to such an initial access.

A device such as a reduced BW UE or device may also add a payload to thePRACH preamble transmission (e.g. transmitted at 1 in FIGS. 39 and 40).In such an embodiment, when a eNB or cell may receive this payload froma device, the eNB or cell may understand the device to be a reduced BWdevice and may act in accordance with that knowledge, for example, byacting in accordance with one or more of the solutions described herein.

Additionally, an indication to and/or from a mobile management entity(MME) may be provided and/or used as described herein. Although areduced BW operation of a device may seem to be relevant (or onlyrelevant) between a device and a eNB or cell as the eNB or cell mayorshould ensure communication with the device in the desired BW, it may beuseful for a MME or another network entity to have information regardingsuch operation as well. This may enable the network to be (or continueto be) aware that a device may be a reduced BW device or may have alimitation in its BW support, when such UE/device may be in Idle mode orwhen it may not be connected (e.g. RRC connected) in the network.

The BW support of a given device may include or consider at least one ofthe following items (e.g. that may be useful for a MME or anothernetwork entity to have, store, have knowledge of, or otherwise provideor use as described herein). For example, BW support of a device mayinclude or consider whether or not the device may be a reduced BWdevice. It may include or consider whether or not the device may supporta full system or cell BW, which may be or may be up to 20 MHz, in the ULand/or DL. It may include or consider whether or not the device supportsfull system or cell BW, which may be or may be up to 20 MHz, in the DL,which may include the DL control region and the DL data region, or inthe DL data region. It may include or consider what maximum BW thedevice may support in the DL, which may include the DL control regionand the DL data region, or in the DL data region. The BW which may beincluded or considered may be indicated by a number of RBs or a value orother indication from which the supported number of RBs may bedetermined. The supported BW or RBs may be different for the control anddata region and may be provided separately. BW support of a device mayinclude or consider the starting frequency of the supported BW, forexample, if the supported BW may not be at the center of the full systemor cell BW. It may consider whether or not the BW or maximum set of RBsthat the device may support may be (or may need to be) in a window ofconsecutive RBs within the full system BW or whether the RBs may belocated, for example, non-consecutively or in non-consecutive groups, aslong as the total number of RBs may not exceed the maximum number thatmay be supported by the device. In one embodiment, the BW support of agiven device may be included as part of its subscription information,for example, in its subscription record which may, for example, be in asubscriber database. The MME or another network entity may then obtainthe BW support of a device, for example, from the home subscriberservice (HSS) during the registration and/or authentication procedure(e.g. via such subscription information). The information may beprovided and/or retrieved based on the device ID (e.g. an IMSI) of thedevice.

In another embodiment, the MME or another network entity may obtain suchdevice BW support information from other network nodes, for example,from at least one of the following: a MTC-Inter Working Function (IWF)which upon MTC device triggering from a MTC-server (e.g. a MTC-ServiceCapability Server (SCS)) may retrieve the UE/device subscriptioninformation from the home subscriber service (HSS) and may pass thedevice specific information to the serving MME of the device which maybe the MME for MTC device triggering for the device; another MME due toUE/device mobility or due to MME overload reduction; and the like.

According to yet another embodiment, a reduced BW device may provide anetwork entity (e.g. a network controlling entity) such as a MME with anindication that it may be a reduced BW device or with its BW supportduring at least one of the network registration actions such as anattach (e.g. in the “ATTACH REQUEST” message) or during device or UEmobility management actions such as tracking area update (TAU) (e.g. inthe “TRACKING AREA UPDATE REQUEST” message). For example, the device mayinclude such BW support information in at least one of theaforementioned messages itself, or in at least one of its UE or devicecapability or network support feature attribute IEs such as “UE networkcapabilities,” “MS network capabilities,” “MS Classmark 2,” MS Classmark3,” “MS network feature support,” and the like.

The MME or other network entity may provide this information to an eNB,for example, in support of certain procedures in which the eNB may nothave this information. For example, the MME or other network entity mayprovide this BW support information (e.g. which may include one or moreitems of information which may be provided separately or in certaincombinations such as in one or more IE), to an eNB in association withpaging (e.g. with an Si PAGING message) for a given UE or device whichmay be attached but not connected, (or detached/unattached but known tobe located in the paging area), so the eNB may know to page this devicein a certain or reduced BW.

As described herein, a device may provide its BW support to an eNB orcell and/or the eNB, or cell may save the BW support of the device.

As described herein, system information may be provided and/or used suchthat reduced BW devices, also referred to herein as narrower BW devices,may obtain system information. In such embodiments, ePDCCH may be anexample and may be replaced by M-PDCCH, other inband signaling (e.g. inthe PDSCH region) or other means to convey DL control information to anarrower BW device. Such embodiments described may be used individuallyor in combination.

For example, existing broadcast SIBs may be used such as one or more ofthe existing SIBs may be used by the narrower BW device. In thisembodiment, these SIBs may be allocated resources in the BW that thenarrower BW devices may access.

To, for example, enable a narrower BW device to determine the resourcesused for system information and/or read system information, one or moreof the following may apply, for example in a cell that may supportnarrower BW devices.

For example, in one embodiment, certain existing SIBs may be (e.g. ormay typically be or may always be) in the narrower BW in a cell that maysupport a narrower BW device. The certain existing SIBs may be each SIB(or all SIBs) or may be a limited set of SIBs that may be applicable tonarrower BW devices or low-cost devices. The narrower BW may be in afixed location such as the center RBs of the system BW or may besemi-statically or dynamically changed (e.g. via PHY signaling such as aDCI format). A device may be told, for example, by higher layersignaling that may be broadcast or dedicated signaling which (e.g.,which of the) existing SIBs may be found in the supported bandwidth.

For subframes carrying certain or each of the SIBs, the number of OFDMsymbols for PDCCH may be fixed (e.g. so the device or UE may not or maynot need to read PCFICH), for example, to 3 symbols. For subframescarrying SIB1, the number of OFDM symbols for PDCCH may be fixed (e.g.,so the device or UE may not or may not need to read PCFICH), forexample, to 3 symbols.

In an embodiment, an ePDCCH in one subframe (e.g., subframe n) may beused to inform the location of a SIB in an upcoming subframe (e.g.subframe n+x; x>=0). The ePDCCH DCI format may include the necessaryresource information. A PDSCH (e.g. in subframe n) that may be indicatedby the ePDCCH may provide additional information regarding the upcomingSIB (e.g. the scheduling and/or resource information). The relationshipbetween n and n+x may be known or the relationship (e.g. the value of x)may be provided by the DCI format or a PDSCH in subframe n. For example,the ePDCCH may be 1 subframe, or 1 DL subframe before the subframe inwhich the upcoming SIB will occur. In another example, the ePDCCH may bein the same subframe, but a number (e.g. 1) frame before the frame inwhich the upcoming SIB may occur. n and n+x may be specific subframes.For example, for SIB 1 which may be in subframe 5, the ePDCCH may be insubframe 0. The location may include the RBs. x may be 0 such thatePDCCH in one subframe (e.g., subframe n) may be used to inform thelocation of a SIB in the same subframe (i.e., subframe n). ePDCCH in onesubframe (e.g. subframe n) may be used to inform the location of SIB 1in an upcoming subframe (e.g., subframe n+x). According to an exampleembodiment, the ePDCCH used to inform (e.g. directly or via PDSCH) thelocation of an upcoming SIB may have a known schedule and/or resources.

In another embodiment, ePDCCH may be used to inform the location of aSIB (e.g. a new SIB) or other PDSCH that may provide scheduling and/orlocation information for multiple (e.g., one or more additional) SIBs.This ePDCCH may have a known schedule and/or resources.

Additionally, the location of a SIB or PDSCH may be informed orindicated (e.g., provided) by a grant (e.g. a DL grant) for the SIB orPDSCH where such grant may be included in, decoded from, or otherwisedetermined from an ePDCCH. The grant may include resource information aswell as parameters which may be used to read and/or decode the SIBand/or PDSCH such as MCS. For ePDCCH to indicate the location of SIBs,SI-RNTI may be used. ePDCCH for one or more of these SIBs may have aknown schedule and/or resources.

Broadcast information may also be provided and/or used as describedherein. For example, in a cell with large BW (e.g. larger than thatsupported by a narrower BW UE or device such as an MTC device), separateSIBs or other PDSCH may be provided to support a narrower BW device. Insuch embodiments, one or more of the following may apply. The new SIBsmay be in the supported narrower BW where the narrower BW may be in afixed location such as the center RBs of the system BW or may besemi-statically or dynamically changed (e.g. via PHY signaling such as aDCI format). The device may read one or more of the new SIBs instead ofone or more existing SIBs. The device may read one or more new SIBs inaddition to certain existing SIBs which may be transmitted in thenarrower BW that the device may support. The device may look for a newSIB based on an existing SIB not being supported in the narrower BW. Thedevice may determine that an existing SIB may not be supported in thenarrower bandwidth from the resource allocation of that SIB, forexample, provided in a PDCCH or ePDCCH scrambled with an SI-RNTI.Additionally, a new RNTI may be used for the new SIB(s). The ePDCCH orPDCCH may be used to inform the devices the location, for example, PDSCHlocations, of the SIBs. For subframes carrying these SIBs, the number ofOFDM symbols for PDCCH may be fixed (e.g. so the devices or UEs may notor may not need to read PCFICH), for example, to 3 symbols. ePDCCH forone or more of these SIBs may have a known schedule and/or resources.Certain SIBs (e.g. one or more SIBs) may have a known schedule in time(e.g. which subframes) and/or RBs. There may be a SIB similar to SIB 1that may have a known schedule and/or which may provide the schedule forother SIBs. These SIBs may carry the same information as the existingSIBs or may carry a subset and/or different information. ePDCCH may beprovided for each SIB or one ePDCCH may provide information for locatingand reading multiple SIBs.

The location of a SIB or PDSCH may be informed or indicated (e.g.provided) by a grant (e.g., DL grant) for the SIB or PDSCH where suchgrant may be included in, decoded from, or otherwise determined from anePDCCH. The grant may include resource information as well as parameterswhich may be used to read and/or decode the SIB/and/or PDSCH such asMCS. For ePDCCH indicating the location of SIBs, SI-RNTI or anotherspecific RNTI may be used.

Additionally, in embodiments, predefined and/or known scheduling for DLControl may be used and/or provided. For example, certain ePDCCHs mayhave a known schedule and/or resources defined, for example, to enablethe narrower BW devices to obtain system information without reading theassociated PDCCH which may span a larger BW than the device may be ableto decode. These ePDCCHs may be referred to as pre-defined ePDCCHs andthey may have a predefined set of corresponding configurationparameters. As described herein, ePDCCH (e.g. predefined or not) may bean example and may be replaced by M-PDCCH, other inband signaling (e.g.in the PDSCH region) or other means to convey DL control information tonarrower BW device.

According to an example embodiment, the predefined ePDCCH may carrygrants for UL and/or DL data transmissions; grants for SIBs; grants fordata including the configuration parameters of the regular ePDCCH; andthe like. In this embodiment, once the device may receive theconfiguration for the regular ePDCCH, it may monitor their correspondingsearch spaces.

Additionally, the frequency-domain and/or time-domain locations of thepredefined ePDCCH may be configured according to one or more of thefollowing. For example, the frequency-domain position of the predefinedePDCCH may be fixed to the minimum bandwidth of 6 RBs, or the BW knownto be supported by the narrower BW devices (e.g. which may be 5 MHz), orany other suitable reduced bandwidth. In another example, thefrequency-domain position of the predefined ePDCCH may be located at thecenter of the actual system bandwidth or alternatively, at a frequencylocation shifted with respect to the system center frequency. In anotherexample, the time-domain position of the predefined ePDCCH may be fixedto a certain subframe, subframes, or a set of subframes, and/orsubframes within a subframe. In another example, the device may expectthe predefined ePDCCH grants with a certain pre-defined frame and/orsubframe periodicity. For example, the predefined ePDCCH may exist inthe 5^(th) subframe of each 4th frame with a periodicity of 40 ms. Insuch an embodiment, the device may not expect a predefined ePDCCHoutside of those configured subframes. In another example, the devicemay receive the predefined ePDCCH within the configured frequency-domainposition in a subframe. In this embodiment, the device may use blinddecoding to detect the existence of the predefined ePDCCH in eachsubframe. In another example, the physical resources allocated to thepredefined ePDCCH may be used to transmit other information such as DLdata. In another example, for the subframes carrying predefined ePDCCH,the number of OFDM symbols for PDCCH may be fixed (e.g. to avoid theneed for UE to read PCFICH) to 3 symbols.

A predefined ePDCCH may grant a transmission according to the processingof a network or system such as an LTE system with the same reducedbandwidth of the predefined ePDCCH. For example, a system with anoriginal bandwidth of 100 RBs may also support devices in areduced-bandwidth of 25 RBs. The ePDCCH designated for those devices inthe reduced-bandwidth may be processed (e.g. encoded, interleaved, andthe like) and allocated to 25 virtual RBs according to the rules andspecifications of a system such as an LTE system with 25 RBs. Then, inan embodiment, those 25 virtual RBs may be mapped to the actual 25 RBsin the reduced-bandwidth region. Such an approach may enable thereception of the ePDCCH by devices without accessing the whole systembandwidth of 100 RBs.

A predefined ePDCCH may grant a transmission according to one or more ofthe following. In one example, a subframe with a static or dynamicsubframe offset may be compared to the subframe location of the samegrant in a system such as an LTE system with the same reduced bandwidth.Such a subframe offset may be predefined for the devices or may belinked implicitly or explicitly to other parameters of the system. Anexample of the latter may be the case where the subframe offset may belinked to the frame and/or subframe location of the received grant.

In another example, a subframe with a static or dynamic RB offset may becompared to the RB location of the same grant in a system such as an LTEsystem with the same reduced bandwidth. Such a RB offset may bepredefined for the devices or may be linked implicitly or explicitly toother parameters of the system. An example of the latter may be the casewhere the RB offset may be linked to the RB location of the receivedgrant within the predefined set of the RBs for the predefined ePDCCH.

Paging, for example, for narrower BW devices, may be provided and/orused as described herein. In paging, one or more of the following mayapply. For example, ePDCCH may be used to inform the location of thepaging channel PDSCH when the device or UE to be paged may be known tobe a narrower BW device. In such an embodiment, ePDCCH may be sent inthe paging occasion associated with the UE or device (e.g. MTC device)based on its UE or device ID or in each paging occasion of the cell. Inanother example, ePDCCH may continue to be used to inform of the page inthe paging occasion(s) until the page may be terminated (e.g. based onthe page being answered or time out with no answer). In another example,the location of the ePDCCH RBs for paging may be provided in signalingsuch as RRC signaling where such signaling may be broadcast or dedicatedsignaling.

In another example, a new paging schedule may be provided for a narrowerBW device which may not be a function of the UE or device ID. Forexample a new PF and/or PO schedule may be identified for a narrower BWdevice for which ePDCCH may be used to inform the location and/or otherconfigurations (e.g., configuration parameters) of the paginginformation or paging channel. The schedule may be provided by systeminformation (e.g. via broadcast). In another example, to page a group ofUEs together, a group paging function may be introduced. The pagingschedule, e.g., for the group paging, may be independent of UE or deviceID and/or a group of UEs or devices may be told to read the same pagingchannel. In another example, a ePDCCH may be used in addition to PDCCHin the paging occasions.

According to an example embodiment, RBs that the device or UE may decodeor attempt to decode in the data region which may include PDSCH RBsand/or ePDCCH RBs, for example, to receive a page or paging data or toobtain paging or paging related information, may be located in a set ofRBs that may be within the BW or RBs of the reduced BW UE or device. Thelocation of those RBs and the device's or UE's understanding of thatlocation may be in accordance with one or more of the embodimentsdescribed herein.

According to an embodiment, a new P′-RNTI may be provided for pagingreduced BW devices. In such an embodiment, the reduced BW devices maymonitor PDCCH or ePDCCH and may blind decode using the new P′-RNTI todetermine if there may be paging data (e.g. PDSCH or PDSCH which may becarrying PCH) for the device. If such paging data may exist, it may belocated in the BW or RBs the device may support.

According to an embodiment, a single DCI may be used to indicatemultiple (e.g. 2) PDSCH blocks where certain blocks (e.g. 1) may besuitable for reception and decoding by reduced BW devices and the others(e.g. 1 other) may not.

For devices (e.g. UEs or MTC devices) in a Connected Mode, an eNB mayhave knowledge of which devices may be narrower BW devices and may useePDCCH for paging for Connected Mode devices that may be known to benarrower BW UE/MTC devices. Alternatively, dedicated signaling may beused instead of the paging channel for devices that are known to benarrower BW devices. The eNB may transmit PDSCH carrying paging datawhich may include paging data (e.g. PCH) for at least one Connected Modedevice that it may know to be a narrower BW device in the BW and/or RBsthe narrower BW device may support. The eNB may transmit a PDSCHcarrying paging data (e.g. PCH) for at least one Connected Mode devicethat it may know to be a narrower BW device and for at least one otherdevice, such as one that is not a narrower BW device, in the BW and/orRBs the narrower BW device may support.

For devices (e.g. UEs or MTC devices) in an Idle Mode, an eNB may notretain knowledge of which devices may be narrower BW devices. Thenetwork entity that may request the page, for example the MME, mayprovide that information to the eNB, for example, with the pagingrequest. In an embodiment, the ePDCCH may be used for paging for IdleMode devices that may be known to be narrower BW devices. The eNB maytransmit PDSCH carrying paging data which may include paging data (e.g.PCH) for at least one Idle Mode device that it may know to be a narrowerBW device in the BW and/or RBs the narrower BW device may support. TheeNB may transmit a PDSCH carrying paging data (e.g. PCH) for at leastone Idle Mode device that it may know to be a narrower BW device and forat least one other device, such as one that may not be a narrower BWdevice, in the BW and/or RBs the narrower BW device may support.

As described above, the ePDCCH may be an example and may be replaced byM-PDCCH, other inband signaling (e.g., in the PDSCH region) or othermeans to convey DL control information to a narrower BW device.

Cell selection and/or reselection, for example for a narrower bandwidthdevice, may be provided and/or used as described herein. For example, atypical cell selection procedure may involve a device (e.g. a UE)finding a best cell based on measurements, and then determining if thecell may be suitable for camping. This may include determining if thecell belongs to a Public Land Mobile Network (PLMN) the device mayconnect to and whether the cell may or may not be barred among othercriteria.

In embodiments, a device may use additional criteria for determiningwhether or not the cell is suitable for camping on. One such criterionmay be whether the cell may support narrower bandwidth devices. If anarrower BW device may determine that a cell may not support narrower BWdevices or may not support its narrower BW, the device may consider thecell unsuitable, for example, for cell selection and/or reselection.

Additionally, support for narrower BW devices may indicate that the cellmay assign resources, for example, PDSCH resources, to a narrower BWdevice in the BW it may support. For example, if a device may supportreception of 12 RBs, the cell may assign this device PDSCH resources of12 RBs or fewer, for example, in a given subframe.

The device may determine whether a cell may support narrower BW devices,and possibly whether it may support the BW of the device or of narrowerBW devices, based on one or more of the following: an indication in aMIB as described herein; an indication in SIB1 or another SIB (e.g. oneor more of a bit, flag, one or more BWs, or another indication); anindication in SIB1 that new and/or special SIB(s) for narrower BWdevices are being broadcast; a new and/or special SIB(s) for narrower BWdevices that may be found by the device to be present; and the like.

The device (e.g., UE or MTC device) may determine that a cell does notsupport narrower BW devices (or narrower BW devices with the BW of thisdevice) based on at least resources for SIB1 (or another SIB) beingallocated in a BW, (e.g., number or RBs and/or location), that thedevice does not support and/or new and/or special SIB(s) for narrower BWdevices are not found by the device.

If the device may be able to read PDCCH, the normal mechanism forobtaining the resource assignment for SIBs in PDSCH may be used (e.g.via PDCCH scrambled with SI-RNTI). If not, an alternate method such asone described herein may be used. For example, a device may do one ormore of the following. The device (e.g., UE or MTC device) may choose acell, for example, based on measurements. The device may read the MIBand the MIB may provide information to enable the device to read PDCCHto obtain the location of SIB1. The device may look for the PDCCH whichmay give it the location (e.g. resource allocation) of SIB1. If the SIB1resource allocation may exceed the BW that may be supported by device,the device may consider this cell unsuitable and may then try to findanother cell that may be suitable. If the SIB1 resource allocation maybe within the BW that may be supported by the device, the device mayread SIB1, which may include information on whether the cell may supportnarrower BW devices. The device may consider a cell unsuitable and maythen try to find another cell that may be suitable if one or more of thefollowing may be true: if SIB1 may not include an indication that thecell may support narrower BW devices; if SIB1 may include an indicationthat the cell may not support narrower BW devices; if SIB1 may includean indication of the narrower BW supported and that BW may be largerthan the BW the device supports; and the like.

As another example, if after reading SIB1 as described above, the device(e.g., UE or MTC device) may determine that the narrower BW SIB(s) maynot be broadcast in this cell (e.g. SIB1 may not indicate that they maybe broadcast), the device may consider the cell unsuitable and may thentry to find another cell that may be suitable.

As another example, if the device may determine that the narrower BWSIB(s) may not be broadcast in a cell, the device may consider the cellunsuitable and may then try to find another cell that may be suitable. Away to determine that the SIB(s) may not be broadcast in the cell may beto keep looking for them, for example, over their expected broadcastperiod and repetition rate (e.g. for some time and/or based on a timer),until it may be reasonably certain that they are not being broadcast.

As another example, the device may look for a SIB or other transmissioninstead of, or in addition to, SIB 1. This SIB or other transmission mayhave a known schedule and/or other parameters to enable the device toknow when to look for it or know when to monitor a control channel suchas PDCCH or ePDCCH to find it. The device may monitor a control channelsuch as PDCCH or ePDCCH to determine whether a SIB or other transmissionrelevant to reduced BW operation may be present in a subframe and whatresources may be assigned to it. An RNTI which may be different fromSI-RNTI may be used. The device may learn from this SIB or othertransmissions at least one of whether the cell may support reduced BWdevices, parameters relating to the reduced BW operation of the cell, orePDCCH configuration for the cell, among others.

For cell reselection, if the highest ranked cell or best cell accordingto absolute priority reselection rules may not support narrower BWdevices or the narrower BW of the device, the device may not considerthe cell for reselection.

Additionally, in embodiments, an indication as to whether neighbor cellsmay support narrower BW devices may be included in the neighbor listinformation. This may include support or non-support and/or the BW (orBWs) supported.

In embodiments, a device may measure (or only measure) cells it may knowsupport narrower BW devices or its narrower bandwidth; a device mayconsider (or only consider) for reselection cells it may know supportnarrower BW devices or its narrower bandwidth; a device may be asked (ormay only be asked) to measure cells that may support narrower BW devicesor its narrower bandwidth; and the like.

According to an example embodiment, a device, e.g., a reduced BW devicewhich may be a UE or MTC device, may be provided with a list of cellsthat may support narrower BW devices and/or its narrower BW. The listmay be preprogrammed, for example, in the universal subscriber identitymodule (USIM)), may be provided to the device via operations,administration and maintenance (e.g. OA&M), or may be provided to thedevice by higher layer signaling. The list may include, for example foreach cell or group of cells which may be in the list, one or more of acell ID, frequency, PLMN, system BW, narrower BW supported, and thelike.

A device (e.g., UE or MTC device) may read the MIB, SIB1, or another SIBor SIBs of a neighbor cell to determine if it may support narrower BWdevices or its narrower bandwidth, for example, when such informationmay not be available to it otherwise such as in preprogrammed orsignaled cell information such as neighbor cell information. Since anarrower BW device may be expected to be a low rate device, it may havetime to obtain and read such information.

Additionally, a device may store information it may learn about supportfor reduced BW devices by certain cells such as cells it may havepreviously visited or cell, e.g., neighbor cell, information it may havereceived. The device may store this information along with cellidentification which may include one or more of PLMN ID, physical cellID, tracking area ID, among others. The device may use this informationto exclude certain cells such as cells it may have learned may notsupport reduced BW devices from its cell selection and/or reselectioncandidates and/or neighbor cell measurements. In an embodiment, theremay be a time limit on how long this exclusion may be permitted.

As described herein, a narrower bandwidth device connection proceduremay be provided and/or used. For example, a cell that may supportnarrower BW devices may provide Random Access Responses (RAR), e.g., allRAR, in the narrower BW that it may support. If it may support multiplenarrower BWs, it may provide RAR, e.g., all RAR, in the narrowest BW itmay support. If the RAR from a cell may be received by a device in a BWor RBs it may not support, or if the RAR from a cell may be indicated toa device to be located in a BW or RBs it may not support, the device mayunderstand that the cell may not support narrower BW devices or itsnarrower BW and may or may need to reselect to a new cell.

The device may provide an indication in its RRC connection request thatit may be a narrower BW device and may include an indication of the BW(e.g. the largest BW) it may support. Prior to receiving the messagethat may identify whether a device may be a narrower BW device, a cellthat may support narrower BW devices may provide DL assignments to thatdevice in the narrow BW or the narrowest BW it may support.

If a device may be assigned resources (e.g. DL resources), in a BW itmay not support, the device may consider this to be an error. The devicemay wait to see if this may persist before declaring a failure (e.g.possibly radio link failure) and may (e.g. possibly) look for a new cellto connect to. If such an assignment may be received prior to indicatingthat it may be a narrower bandwidth device, the device may understandthat the cell may not support narrower BW devices or its narrower BW andmay or may need to reselect to a new cell.

A handover procedure involving reduced bandwidth devices may be providedand/or used. For example, one or more of the following items or actionsmay be used and/or may apply. An eNB may handover (or may limit handoverof) a reduced BW device to a cell that may support reduced BW operation.In the X2 handover request from a source eNB to a target eNB, the sourceeNB may include an indication as to whether the device to be handed overmay be a reduced BW device and/or the BW support of the device (e.g. asdescribed herein above). In the X2 reply from the target eNB, the targeteNB may reject the request if it may not support reduced BW devices orat least one aspect of the BW support indicated for the device for whichthe request may have been made. The rejection may include indication ofthis cause. A first eNB, (e.g. a source eNB which may want to handover areduced BW device to a target eNB) may expect a certain response in anX2 reply (e.g. a X2 reply to an X2 handover request from the source eNB)from a second eNB, (e.g. the target eNB for a handover), which wouldmean that it may support reduced BW operation. If the first eNB may notreceive the expected response from the second eNB, it may understandthat the second eNB may not support reduced BW operation. An eNB mayobtain information regarding reduced BW support of a cell belonging toanother eNB via X2 signaling to and/or from that eNB, (e.g. via an X2SETUP REQUEST or an ENB CONFIGURATION UPDATE message). An eNB may obtaininformation regarding reduced BW support of a cell belonging to anothereNB via the network (e.g. via OA&M). An eNB may include in its neighborrelation table information regarding the full and/or reduced BW supportof its neighboring cells.

When a handover may be performed for a reduced BW device, if acontention free random access procedure may be performed, for example,to gain synchronization in the new cell, the cell may provide the randomaccess response in the supported BW of the device since it may know thatthe device may be a reduced BW device based on the handover request overthe X2. If a contention based random access procedure may be performed(e.g. along with or in conjunction with a handover), one or more of therelated embodiments described herein may be applied.

Receiver complexity may also be reduced as described herein. Forexample, systems and/or methods may be provided that may reduce orminimize the implementation complexity of a device receiver such as a UEor MTC receiver. Given the low throughput that may be required in adevice, a compact set of functions may be defined for devices and thefunctions may be configured to coexist with legacy devices or UEs (e.g.Rel-8/9/10). The system may use a device configured with a singletransmission antenna with two receive RF chains as described herein.

A time shared RNTI may be used and/or provided to help reduce suchreceiver complexity. For example, in some embodiments, a new RNTI for adevice may defined as a device RNTI such as a MTC-RNTI which may use fordownlink and uplink data transmission. In such an embodiment, an eNB maysupport more than 20000 MTC devices in a cell at the same time. Innetworks such as LTE networks, an RNTI may given to a specific device orUE as an ID as a result of the random access process in a cell, and itmay be masked on a 16-bit CRC in the PDCCH such that the device or UEmay blindly detect its control channels by checking the RNTI afterdecoding a PDCCH. However, to support narrow BW devices such as MTCdevices and legacy UEs simultaneously in a cell, the number of RNTI maynot be enough considering that multiple RNTIs may be used for a singlelegacy device or UE support. Therefore, in one embodiment, the same RNTImay be shared with multiple devices. According to an example embedment,the throughput requirement for a device such as a MTC device may berelatively low such that the DL and/or UL grant may be transmittedwithin the restricted number of subframes. Although device RNTI or anMTC-RNTI may be shared with multiple devices, the false alarmprobability may be kept as it is in the previous networks because thedevice or MTC-RNTI may be used in a non-overlapped manner and a devicemay be forced to monitor the subset of the subframe.

In an embodiment, from a device perspective (e.g. MTC perspective), adevice or MTC-RNTI and valid subframe information may be providedtogether such that the device may monitor PDCCHs configured by thedevice or MTC-RNTI for a subset of subframe. The subframe may be definedas follows. The valid subframe for a device or MTC-RNTI may beconfigured with 40 ms duty cycle. As such, a 40 bits bitmap may be usedto indicate which subframe may be monitored for the PDCCHs configured bythe device or MTC-RNTI. The valid subframe index may be provided in thefirst subframe of a radio frame. As such, the radio frame header may bedefined to provide the subframe. The valid subframe may be defined as apredetermined starting point within the duty cycle. As one example, thestarting subframe index N with duty cycle M may be provided to a devicesuch as a UE or MTC device. Then, the device may monitor if the subframeindex n may satisfy the condition (n−N)modM=0 and/or the duty cycle maybe defined with multiples of 8. One such example of a time shared deviceor MTC-RNTI may be shown in FIG. 41.

Additionally, a device such as an MTC device may support transmissionmode and/or a single transmission scheme that may rely on commonreference signal (CRS) regardless of the number of eNB antenna ports.The CRS may be defined (e.g. in Rel-8) according to the number ofantenna ports at an eNB transmitted and supportable up to 4 antennaports. Because the CRS may be used for downlink control channeltransmission including PCFICH, PDCCH, and PHICH, a device such as an MTCdevice may read CRS for coherent demodulation of downlink controlchannels. Therefore, in one embodiment, a single transmission schemesuch as transmit diversity scheme may be used for PDSCH transmission fordevice such as an MTC device. In an embodiment, the transmit diversityscheme (e.g. SFBC) may provide diversity gain and robustness of datatransmission when channel state information may not be available at theeNB transmitter. In the case of the single antenna port being used at aneNB transmitter, a single-antenna port such as port-0 may be used forthe PDSCH transmission. The PDCCH and PDSCH configured by MTC-RNTI(CRS-based) may be shown in the table of FIG. 42.

An alternative method may be based on a DM-RS based transmission scheme.For example, a single device or UE-specific antenna port may be definedto achieve beamforming gain. In addition, the receiver design may besimpler than the CRS based transmission scheme, because the same singledevice or UE-specific antenna port may be used regardless of the numberof antenna port at the eNB transmitter. As such, a device such as an MTCdevice may not implement multiple receivers which fit to transmissionschemes. Such an embodiment may be configured according to the table inFIG. 43 where PDCCH and PDSCH may be configured by device or MTC-RNTI(e.g. DMRS-based).

According to an example embodiment, the DM-RS port for DM-RS basedtransmission may be not restricted to port-7. As such, other DM-RS portsmay also used such as port-5, port-{8, 9, 10, . . . , 14}. Additionally,to support multi-user MIMO, the DM-RS port may be indicated by PDCCHand/or higher layers.

In a further embodiment, both CRS-based and DMRS-based transmissionmodes may be used for a device such as an MTC device and configured by aDCI format. Also, the transmission scheme may be configured by a higherlayer such that if a CRS-based transmission scheme may be configured, adevice such as an MTC device may monitors DCI format 1A, otherwise DCIformat 1 may be monitored to reduce the blind detection trials. Such anembodiment may be configured according to the table in FIG. 44 wherePDCCH and PDSCH may be configured by device or MTC-RNTI (e.g.CRS/DMRS-based).

PDCCH and/or PDSCH reception may also be provided and/or used. Forexample, a device such as an MTC device may receive a specific CCEaggregation level for its PDCCH blind detection. According to anembodiment (e.g. in Rel-8), the CCE aggregation level may be {1, 2, 4,8} and a device may attempts CCE aggregation levels for the PDCCHdetection thereby increasing the blind decoding complexity. To minimizethe PDCCH decoding complexity, in one embodiment, an eNB may configure aspecific CCE aggregation level and/or a subset of CCE aggregation levelfor the device or MTC device. Hence, a device such as an MTC device maymonitor the designated CCE aggregation level resulting in reduceddecoding complexity. Furthermore, the CCE aggregation level may be tiedto the subframe index. This alternative method may support variouscoverage without blind detection by defining subframe specific CCEaggregation level. For example, a device such as an MTC device maymonitor CCE aggregation level 1 in the subframe n and CCE aggregationlevel 2 in the subframe n+1 and so forth. As such, the PDCCH coveragemay be defined according to the subframe index. The subframetransmitting larger CCE aggregation level such as 4 and 8 may providebetter PDCCH coverage.

In example embodiments, the CCE aggregation level may be tied with thesubframe index using one or more of the following techniques. The CCEaggregation level for the PDCCH configured with MTC-RNTI may be definedaccording the subframe index in cell-specific manner. In this method,broadcasting channel may be used for the CCE aggregation levelinformation or the CCE aggregation level may be predefined.Additionally, the CCE aggregation level for the PDCCH configured withMTC-RNTI may be defined in a device or UE-specific manner via higherlayer signaling. The CCE aggregation level for the PDCCH configured withMTC-RNTI may be implicitly indicated by the device or MTC-RNTI.According to an example embodiment, the device or MTC-RNTI value beingwithin a specific range may imply the CCE aggregation level. An exampleembodiment of the subframe specific CCE aggregation level may bedepicted in FIG. 45.

A device such as an MTC device may receive the corresponding PDSCH inthe subframe n+k upon which the device or MTC may receive PDCCH in thesubframe n. The k can be defined as a positive integer number including1, 2, 3, and 4. In this embodiment, the device or MTC device may assumethat there may be no PDCCH for the device or MTC device in the subframen+1. This may relax the receiver processing time for PDCSCH reception.In addition, a device such as an MTC device may assume that the PDSCHmay span multiple subframes in the same resource blocks.

Additionally, in embodiments, burst based semi-persistent scheduling maybe used and/or provided as described herein. For example, a device suchas an MTC device may have burst traffic in which the device may wake upfor a short time period and may report the information within the giventime. The physical resource in time frequency domain may be defined viahigher layer signaling and the PDCCH configured by a device or MTC-RNTImay trigger the burst traffic transmitting and/or receiving untilanother PDCCH configured by a device or MTC-RNTI may release theresources. Because the time/frequency resources for each device mayallocated from a higher layer, the triggering PDCCH may be shared withmultiple devices.

As described herein, a new DCI format for the trigger and/or release ofphysical resources may be defined in one embodiment. For example, DCIformat 3B may be defined for a device or MTC command in which the state‘0’ may imply triggering and ‘1’ may imply release the resources, orvice-versa. In the DCI format 3B, multiple device or MTC command bitsmay be included such that an independent bit for each device may beallocated, thus, allowing a flexible device specific trigger and/orrelease.

As an alternative method, two or three bits for a device or MTC commandin the DCI format 3B may be used to indicate multiple status as follows:

2 bit MTC command

-   -   “00”: trigger the burst transmission    -   “01”: retransmission of PUSCH    -   “10”: retransmission of PDSCH    -   “11”: release the burst transmission

3 bit MTC command

-   -   “000”: trigger the burst transmission    -   “001”: retransmission of PUSCH    -   “010”: retransmission of PDSCH    -   “011”: bundling TTI for PUSCH (2 ms)    -   “100”: bundling TTI for PUSCH (3 ms)    -   “101”: bundling TTI for PUSCH (4 ms)    -   “110”: release the burst transmission    -   “111”: reserved

As shown in the examples, the device or MTC command may include triggerand/or release physical resouces, retransmission of PUSCH and/or PDSCH,and a TTI bundling command. The multiple device or MTC commands in DCIformat 3B may transmitted as follows: device or MTC command 1, device orMTC command 2, device or MTC command 3, . . . , device or MTC command N.The position of the device or MTC command in the DCI format 3B may beprovided to a device from higher layer signaling.

A single RF chain device may also be provided and/or used in anembodiment. For example, to reduce the cost of a device such as a UE orMTC device, a device such as an LTE device with single receive antennamay be used and/or introduced. By restricting the number of receiveantennas, the cost-saving in a device such as an MTC device may beachieved by removing the second antenna, one of the RF chains and lowerbaseband processing associated with the second receive path.

One implication on the device such as a UE or MTC device by removing oneof the RF chains may be a reduced coverage due to the lower receiversensitivity. Given that the device may aim to provide the same coverageas the legacy device (e.g. LTE UE), to enhance the coverage of downlinksignaling and control channels, one or more the following solutions maybe employed: power boosting, enhanced control channel designs may beemployed, UL HARQ mechanisms may be eliminated, ACK/NACK repetition maybe provided, autonomous PDSCH retransmissions may be performed, the MCSscheme may be restricted, and the like. For example, in an embodiment(e.g. power boosting), increasing the power may be used as a tool toimprove the coverage of downlink control channels such as PCFICH, PHICHand PDCCH.

Additionally, in another embodiment, enhanced control channel designsmay be employed. Such an embodiment may be beneficial in HetNetscenarios wherein increasing the transmit power may result in higherinterference (e.g. low SINR) for the devices. For example, PCFICH may besemi-statically configured for devices which may imply no specificphysical layer mechanism to indicate the size of the control region interms of the number of OFDM symbols. As for PHICH and PDCCH, the devicemay receive those control channels in the PDSCH region rather than thelegacy control region. By transmitting PHICH and PDCCH in the PDSCHregion, Inter-Cell Interference Coordination (ICIC) may be used to lowerthe impact of inter-cell interference (ICI) on the devices and toenhance the coverage of the control channels.

According to an embodiment, an UL HARQ mechanism may be eliminated. Forexample, a network such as LTE may transmit PHICH in the downlink toindicate the hybrid-ARQ acknowledgements in response to UL data packettransmission. However, a device such as a UE or MTC device may bedesigned without an UL HARQ mechanism to reduce the signaling overhead.In this embodiment, the device may autonomously retransmit the data inconsecutive or predefined subframes without waiting for ACK/NACKfeedback on PHICH.

Additionally, ACK/NACK repetition may be provided and/or used. Forexample, to enhance the PHICH coverage in situations where powerboosting may not be applicable (e.g. interference limited environments),the HARQ ACK/NACK in response to UL data packet transmission may beretransmitted in the downlink. According to such an embodiment, PHICHmay be retransmitted in consecutive or predefined_subframes. Therepetition factor for ACK/NACK retransmission may be configured throughhigher layer signaling (e.g. RRC) depending on the required coverage.

Autonomous PDSCH retransmissions may also be provided and/or used. Forexample, to enhance the coverage of the downlink shared channel, thePDSCH may be retransmitted in consecutive or predefined_subframeswithout waiting for HARQ feedback on PUCCH from the device or UE side.The number of retransmissions may be configured through the higherlayer. In this embodiment, the device or UE may or may not transmit anacknowledgment on the UL. If the device or UE may be expected totransmit feedback, the HARQ acknowledgment may be generated afterreceiving the last retransmitted PDSCH.

According to another example embodiment, the Modulation and CodingScheme (MCS) may be restricted. For example, based on such a scheme, thedevice or UE may receive and/or decode a subset of the modulation andcoding combinations from the set defined for the legacy network such asLTE. For example, the device such as the UE or MTC device may receiveand decode the QPSK modulated signal to meet its recover sensitivityrequirement. This may be to compensate for the 3 dB loss due to theabsence of receive diversity gain as a result of eliminating the secondantenna.

UL enhancements may also be provided and/or used. For example, to reducethe cost of a device, the battery power consumption may be lowered.Given that the major source of inefficiency in transmit power may be thepower back off due to high signal peakiness of the transmit signal, anumber of solutions may be proposed to reduce the signal peakiness forthe uplink of a device. According to an embodiment, by reducing thesignal peakiness, the same coverage as in a network such as LTE may beachieved with the smaller power amplifier. This, in turn, may lower thecost of a device.

For example, partial PUSCH transmissions may be provided and/or used.According to this embodiment, PUSCH may be transmitted on the partialgranted resources in the uplink. This may help increase the power persubcarrier by using a narrower resource allocation in the frequencydomain. For example, PUSCH may be transmitted on the even or oddsubcarriers within the assigned RB(s) while the power per resource blockmay be unchanged. In this embodiment, to support the same transportblock size as in current systems or networks (e.g. LTE Rel-8), eachtransport block may be transmitted in two or multiple subframes.

Also, to maintain the total system throughput, PUSCH transmissions frommultiple devices may be frequency multiplexed (e.g. interlaced). Forexample, one device may use odd subcarriers for PUSCH transmission andanother device may use even subcarriers for its PUSCH transmissions. Thefrequency shift and/or allocations may be indicated to the device as apart of its uplink grant transmitted in the DL.

To enhance the PUCCH coverage when lower power may be used for uplinktransmissions, the HARQ ACK/NACK in response to DL data packettransmission may be retransmitted (e.g. ACK/NACK repetition may beprovided) in the uplink. According to this scheme, PUCCH may beretransmitted in consecutive or predefined subframes. The repetitionfactor for ACK/NACK retransmission may be configured through higherlayer signaling (e.g. RRC) depending on the coverage.

As described herein, the DL HARQ mechanism may be eliminated. Forexample, the network such as LTE may transmit PUCCH in the uplink toindicate the hybrid-ARQ acknowledgements in response to DL data packettransmission. However, a device may be designed without a DL HARQmechanism to reduce the signaling overhead. In this embodiment, the eNBmay autonomously retransmit PDSCH in consecutive or predefined subframeswithout waiting for ACK/NACK feedback on PUCCH.

Additionally, the Modulation and Coding Scheme (MCS) may be restricted.For example, based on this scheme, the device may restricted to use asubset of the modulation and coding combinations and/or transport blocksize from the set defined for the uplink of a legacy network such asLTE. For example, the device may use QPSK modulation for its uplinktransmissions to lower the required power de-rating at its poweramplifier. According to an example embodiment, higher order modulationssuch as QAM16 and QAM64 may have higher cubic metric (and also higherpeak to average power ratio) which may use higher power back-off at thetransmitter. As a by-product of restricted MCS, a more compact DCIformat may also be introduced for the devices. The latter may imply thatthe MCS field of the compact DCI format may be smaller than 5 bits (e.g.3 bits). A more compact DCI format may also increase the achievablecoverage of PDCCH in DL.

Additionally, introducing a new modulation scheme for devices such asπ/M-shifted MPSK modulation schemes including π/2-shifted BPSK mayenable the coverage to be maintained due to a lower signal peakiness(e.g. as compared to that of QPSK even when the maximum transmissionpower may be reduced). By introducing of a new modulation scheme, thetransport block size and MCS signaled on the downlink may be modifiedfor the devices compared to the legacy network such as LTE. This may beaccomplished through remapping of the MCS index received in the DCI toinclude the newly introduced modulation scheme.

A spectrum shaping mechanism in the UL may also be introduced. Forexample, spectrum shaping may be used to further reduce signalpeakiness. In such an embodiment, the use of Root Raised-Cosine (RRC) orKaiser window spectrum shaping may be introduced as a feature for thedevices such as UEs or MTC devices. According to an embodiment, theintroduction of spectrum shaping in the UL may slightly increase thecomplexity at the device, may lower battery power consumption, and/ormay lower cost.

Additionally, uplink control channels may be provided and/or used. Forexample, the following examples may be considered for a device totransmit PUCCH without interfering with a SRS transmission from a legacydevice (e.g. a LTE UE). In one example, different subframes may beconfigured for the device or MTC PUCCH transmission and legacy device orUE SRS transmission, respectively. A device may be configured withsubframe(s) for its PUCCH transmission where the subframe may not be acell-specific SRS subframe (e.g. a Rel-10 cell-specific SRS subframe).For example, the device may be configured to transmit a periodic CSIreport on PUCCH in a subframe which may not be a cell-specific SRSsubframe (e.g. a Rel-10 cell-specific SRS subframe).

In another example, a piggy-back approach for UCI transmission may beused. A device may transmit UCI (e.g., periodic CSI and/or ACK/NACK) onPUSCH in a cell-specific SRS subframe (e.g. Rel-10 cell-specific SRSsubframe). In this embodiment, a PUSCH resource may be allocated ineither a dynamic manner (e.g. UL grant in PDCCH), or semi-statically,(e.g. RRC signaling). If there may be a PUSCH transmission (e.g. forUL-SCH) allocated for the device in a cell-specific SRS subframe (e.g.Rel-10 cell-specific SRS subframe), the device may piggy back the UCItransmission on the PUSCH.

In another example, a shortened PUCCH format may be used in eachcell-specific SRS subframe (e.g. Rel-10 cell-specific SRS subframe). Ifa device may be scheduled to transmit UCI such as ACK/NACK and/orperiodic CSI in a cell-specific SRS subframe (e.g. Rel-10 cell-specificSRS subframe), the device may use a shortened PUCCH format in the givenSRS subframe. According to an example embodiment (e.g. in Rel-10),shortened formats for PUCCH format 1a/b and PUCCH format 3,respectively, may be used. However, there may be no shortened PUCCHformat 2 currently provided that may be used. As such, a shortened PUCCHformat-2 may be defined as described herein. Such a format may bedefined as puncturing the last 2 bits after (20, O) RM coding, forexample, after the periodic CSI sequence with N bits being encoded using(20, N) RM coding, the last 2 bits of the resulting coded bits beingpunctured, yielding to 18 coded bits. Using a different (M, O) RM codingscheme or a block coding, a different (M, N) RM coding may be used for ashortened PUCCH format 2 where M may not be equal to 20. In thisembodiment, the RM coded output bits may be rate-matched to 18 bits.Alternatively, a block coding may be used to produce 18 bit long codeoutput. Such a format may also be defined as using a different set ofbasis sequence for (20, O) RM code to enhance the hamming distance ofthe punctured 18 bit long RM codes.

In another example, periodic CSI transmission may be dropped in acell-specific SRS subframe (e.g. Rel-10 cell-specific SRS subframe). Forexample, the device may drop periodic CSI transmission in acell-specific SRS subframe (e.g. Rel-10 cell-specific SRS subframe).Additionally, the device may be configured with aperiodic CSItransmission such that the device may be configured to not reportperiodic CSI, but report aperiodic CSI.

The examples and embodiments described herein may use the terms narrowerBW and reduced BW interchangeably. In addition, MTC device may bereplaced by UE or device or reduced BW UE or device and be consistentwith the description herein. BW may be replaced by a number or set ofRBs. This number or set of RBs which may constitute the supported BW ofa UE/device such a reduced BW UE/device may be, or may not be, or may berequired to be, or may not be required to be, consecutive in frequency.

Additionally, in the embodiments described herein, ePDCCH may beprovided by an example and may be replaced by M-PDCCH, other inbandsignaling (e.g. in the PDSCH region) or other means to convey DL controlinformation to a narrower BW device.

Furthermore, although features and elements are described above inparticular combinations, one of ordinary skill in the art willappreciate that each feature or element can be used alone or in anycombination with the other features and elements. In addition, themethods described herein may be implemented in a computer program,software, or firmware incorporated in a computer-readable medium forexecution by a computer or processor. Examples of computer-readablemedia include electronic signals (transmitted over wired or wirelessconnections) and computer-readable storage media. Examples ofcomputer-readable storage media include, but are not limited to, a readonly memory (ROM), a random access memory (RAM), a register, cachememory, semiconductor memory devices, magnetic media such as internalhard disks and removable disks, magneto-optical media, and optical mediasuch as CD-ROM disks, and digital versatile disks (DVDs). A processor inassociation with software may be used to implement a radio frequencytransceiver for use in a WTRU, UE, terminal, base station, RNC, or anyhost computer.

1-34. (canceled)
 35. A method implemented by a wireless transmit receiveunit (WTRU) for performing random access, the method comprising: theWTRU sending a preamble using a selected set of physical random accesschannel (PRACH) resources selected from one of a first set of PRACHresources and a second set of PRACH resources; and the WTRU monitoringone of a physical downlink control channel (PDCCH) or a PDCCH associatedwith a machine type communication (MTC) device (M-PDCCH) based on theselected set of PRACH resources used for sending the preamble, whereinthe WTRU monitors the PDCCH if the preamble is sent using the first setof PRACH resources and the WTRU monitors the M-PDCCH if the preamble issent using the second set of PRACH resources.
 36. The method of claim35, further comprising the WTRU receiving a random access response, RAR,via the M-PDCCH based on the preamble being sent on the second set ofPRACH resources.
 37. The method of claim 36, wherein resourcesassociated with the M-PDCCH for monitoring comprise a set of resourceblocks (RBs) within a reduced bandwidth.
 38. The method of claim 35,wherein the WTRU corresponds to a narrow bandwidth long-term evolution(LTE) user equipment (UE) device.
 39. The method of claim 37, wherein asubset of the resources associated with the M-PDCCH is configured foruse by the WTRU.
 40. The method of claim 35, wherein the preamble issent to a full bandwidth network, wherein the full bandwidth networkcomprises an LTE network operating at a bandwidth of 20 MHz, and whereinthe WTRU comprises a low-cost machine type communication deviceoperating at a bandwidth of 1.4 MHz.
 41. The method of claim 37, whereinthe resources associated with the M-PDCCH are monitored in a subframeand at a particular location.
 42. The method of claim 35, wherein thesecond set of PRACH resources correspond to PRACH resources for areduced bandwidth WTRU.
 43. A wireless transmit receive unit (WTRU)comprising a processor configured at least to: send a preamble using aselected set of physical random access channel (PRACH) resourcesselected from one of a first set of PRACH resources and a second set ofPRACH resources; and monitor one of a physical downlink control channel(PDCCH) or a PDCCH associated with a machine type communication (MTC)device (M-PDCCH) based on the selected set of PRACH resources used forsending the preamble, wherein the WTRU monitors the PDCCH if thepreamble is sent using the first set of PRACH resources and the WTRUmonitors the M-PDCCH if the preamble is sent using the second set ofPRACH resources.
 44. The WTRU of claim 43, wherein the processor isconfigured to receive a random access response (RAR) via the M-PDCCHbased on the preamble being sent on the second set of PRACH resources.45. The WTRU of claim 44, wherein resources associated with the modifiedPDCCH for monitoring comprise a set of resource blocks (RBs) within areduced bandwidth.
 46. The WTRU of claim 43, wherein the WTRUcorresponds to a narrow bandwidth long-term evolution (LTE) userequipment (UE) device.
 47. The WTRU of claim 45, wherein a subset of theresources associated with the M-PDCCH is configured for use by the WTRU.48. The WTRU of claim 43, wherein the preamble is sent to a fullbandwidth network, wherein the full bandwidth network comprises an LTEnetwork operating at a bandwidth of 20 MHz, and wherein the WTRUcomprises a low-cost machine type communication device operating at abandwidth of 1.4 MHz.
 49. The WTRU of claim 45, wherein the resourcesassociated with the M-PDCCH are monitored in a subframe and at aparticular location.
 50. The WTRU of claim 43, wherein the second set ofPRACH resources correspond to PRACH resources for a reduced bandwidthWTRU.